diff --git a/linkml/generators/jsonldcontextgen.py b/linkml/generators/jsonldcontextgen.py
index 343874ff..d7067140 100644
--- a/linkml/generators/jsonldcontextgen.py
+++ b/linkml/generators/jsonldcontextgen.py
@@ -165,42 +165,6 @@ class ContextGenerator(Generator):
         if slot_def:
             self.context_body[underscore(aliased_slot_name)] = slot_def
 
-    def add_prefix(self, ncname: str) -> None:
-        """ Add a prefix to the list of prefixes to emit
-
-        @param ncname: name to add
-        """
-        if ncname not in self.namespaces:
-            self.logger.warning(f"Unrecognized prefix: {ncname}")
-            self.namespaces[ncname] = f"http://example.org/UNKNOWN/{ncname}/"
-        self.emit_prefixes.add(self.namespaces._cased_key(ncname))
-
-    def add_mappings(self, defn: Definition) -> None:
-        """
-        Process any mappings in defn, adding all of the mappings prefixes to the namespace map
-        :param defn: Class or Slot Definition
-        """
-        self.add_id_prefixes(defn)
-        mappings = defn.mappings + defn.related_mappings + defn.close_mappings + \
-                   defn.narrow_mappings + defn.broad_mappings + defn.exact_mappings
-        for mapping in mappings:
-            if '://' in mapping:
-                mcurie = self.namespaces.curie_for(mapping)
-                if mcurie is None:
-                    self.logger.warning(f"No namespace defined for URI: {mapping}")
-                    return        # Absolute path - no prefix/name
-                else:
-                    mapping = mcurie
-            if ':' not in mapping or len(mapping.split(':')) != 2:
-                raise ValueError(f"Definition {defn.name} - unrecognized mapping: {mapping}")
-            ns = mapping.split(':')[0]
-            self.add_prefix(ns)
-
-    def add_id_prefixes(self, element: Element) -> None:
-        for id_prefix in element.id_prefixes:
-            self.add_prefix(id_prefix)
-
-
 @shared_arguments(ContextGenerator)
 @click.command()
 @click.option("--base", help="Base URI for model")
diff --git a/linkml/generators/owlgen.py b/linkml/generators/owlgen.py
index 868b7f1a..74ff2a4e 100644
--- a/linkml/generators/owlgen.py
+++ b/linkml/generators/owlgen.py
@@ -39,6 +39,7 @@ class OwlSchemaGenerator(Generator):
             SchemaLoader(METAMODEL_YAML_URI, base_dir=META_BASE_URI, importmap=kwargs.get('importmap', None),
                          mergeimports=self.merge_imports)
         self.metamodel.resolve()
+        self.emit_prefixes: Set[str] = set()
         self.top_value_uri: Optional[URIRef] = None
         self.ontology_uri_suffix = ontology_uri_suffix
 
@@ -119,6 +120,7 @@ class OwlSchemaGenerator(Generator):
                     logging.warning(f'No URI for {m}')
 
     def visit_class(self, cls: ClassDefinition) -> bool:
+        self.add_mappings(cls)
         cls_uri = self._class_uri(cls.name)
         self.add_metadata(cls, cls_uri)
         self.graph.add((cls_uri, RDF.type, OWL.Class))
@@ -235,6 +237,7 @@ class OwlSchemaGenerator(Generator):
         @param slot:
         @return:
         """
+        self.add_mappings(slot)
         # Note: We use the raw name in OWL and add a subProperty arc
         slot_uri = self._prop_uri(slot.name)
         self._add_element_properties(slot_uri, slot)
diff --git a/linkml/generators/prefixmapgen.py b/linkml/generators/prefixmapgen.py
index 7a4c04a9..0df2dd83 100644
--- a/linkml/generators/prefixmapgen.py
+++ b/linkml/generators/prefixmapgen.py
@@ -85,38 +85,8 @@ class PrefixGenerator(Generator):
         # We don't bother to visit class slots - just all slots
         return False
 
-    def add_prefix(self, ncname: str) -> None:
-        """ Add a prefix to the list of prefixes to emit
-
-        @param ncname: name to add
-        """
-        if ncname not in self.namespaces:
-            self.logger.warning(f"Unrecognized prefix: {ncname}")
-            self.namespaces[ncname] = f"http://example.org/UNKNOWN/{ncname}/"
-        self.emit_prefixes.add(ncname)
-
-    def add_mappings(self, defn: Definition) -> None:
-        """
-        Process any mappings in defn, adding all of the mappings prefixes to the namespace map
-        :param defn: Class or Slot Definition
-        """
-        self.add_id_prefixes(defn)
-        for mapping in defn.mappings:
-            if '://' in mapping:
-                mcurie = self.namespaces.curie_for(mapping)
-                self.logger.warning(f"No namespace defined for URI: {mapping}")
-                if mcurie is None:
-                    return        # Absolute path - no prefix/name
-                else:
-                    mapping = mcurie
-            if ':' not in mapping or len(mapping.split(':')) != 2:
-                raise ValueError(f"Definition {defn.name} - unrecognized mapping: {mapping}")
-            ns = mapping.split(':')[0]
-            self.add_prefix(ns)
-
-    def add_id_prefixes(self, element: Element) -> None:
-        for id_prefix in element.id_prefixes:
-            self.add_prefix(id_prefix)
+    def visit_slot(self,  aliased_slot_name: str, slot: SlotDefinition) -> None:
+        self.add_mappings(slot)
 
 
 @shared_arguments(PrefixGenerator)
diff --git a/linkml/generators/pythongen.py b/linkml/generators/pythongen.py
index 7e250e76..a748e558 100644
--- a/linkml/generators/pythongen.py
+++ b/linkml/generators/pythongen.py
@@ -69,28 +69,6 @@ class PythonGenerator(Generator):
             if type_prefix:
                 self.emit_prefixes.add(type_prefix)
 
-    def add_mappings(self, defn: Definition) -> None:
-        """
-        Process any mappings in defn, adding all of the mappings prefixes to the namespace map
-        :param defn: Class or Slot Definition
-        """
-        self.add_id_prefixes(defn)
-        for mapping in defn.mappings:
-            if '://' in mapping:
-                mcurie = self.namespaces.curie_for(mapping)
-                self.logger.warning(f"No namespace defined for URI: {mapping}")
-                if mcurie is None:
-                    return        # Absolute path - no prefix/name
-                else:
-                    mapping = mcurie
-            if ':' not in mapping or len(mapping.split(':')) != 2:
-                raise ValueError(f"Definition {defn.name} - unrecognized mapping: {mapping}")
-            ns = mapping.split(':')[0]
-            self.emit_prefixes.add(ns)
-
-    def add_id_prefixes(self, element: Element) -> None:
-        self.emit_prefixes.update(element.id_prefixes)
-
     def gen_schema(self) -> str:
         # The metamodel uses Enumerations to define itself, so don't import if we are generating the metamodel
         enumimports = '' if self.genmeta else \
diff --git a/linkml/utils/generator.py b/linkml/utils/generator.py
index 52e58d76..cfd44f7e 100644
--- a/linkml/utils/generator.py
+++ b/linkml/utils/generator.py
@@ -9,7 +9,7 @@ from click import Command, Argument, Option
 
 from linkml_runtime.linkml_model.meta import SchemaDefinition, ClassDefinition, SlotDefinition, ClassDefinitionName, \
     TypeDefinition, Element, SlotDefinitionName, TypeDefinitionName, PrefixPrefixPrefix, ElementName, \
-    SubsetDefinition, SubsetDefinitionName, EnumDefinition, EnumDefinitionName
+    SubsetDefinition, SubsetDefinitionName, EnumDefinition, EnumDefinitionName, Definition
 from linkml_runtime.utils.formatutils import camelcase, underscore
 from linkml.utils.mergeutils import alias_root
 from linkml.utils.schemaloader import SchemaLoader
@@ -561,6 +561,46 @@ class Generator(metaclass=abc.ABCMeta):
         return [slot for slot in [self.schema.slots[sn] for sn in cls.slots] if cls.name in slot.domain_of or
                 (set(cls.mixins).intersection(slot.domain_of))]
 
+    def add_mappings(self, defn: Definition) -> None:
+        """
+        Process any mappings in defn, adding all of the mappings prefixes to the namespace map
+        :param defn: Class or Slot Definition
+        """
+        self.add_id_prefixes(defn)
+        mappings = defn.mappings + defn.related_mappings + defn.close_mappings + \
+                   defn.narrow_mappings + defn.broad_mappings + defn.exact_mappings
+        # see https://github.com/linkml/linkml/pull/283
+        #if isinstance(defn, ClassDefinition):
+        #    mappings.append(defn.class_uri)
+        #if isinstance(defn, SlotDefinition):
+        #    mappings.append(defn.slot_uri)
+        for mapping in mappings:
+            if '://' in mapping:
+                mcurie = self.namespaces.curie_for(mapping)
+                if mcurie is None:
+                    self.logger.warning(f"No namespace defined for URI: {mapping}")
+                    return        # Absolute path - no prefix/name
+                else:
+                    mapping = mcurie
+            if ':' not in mapping or len(mapping.split(':')) != 2:
+                raise ValueError(f"Definition {defn.name} - unrecognized mapping: {mapping}")
+            ns = mapping.split(':')[0]
+            self.add_prefix(ns)
+
+    def add_id_prefixes(self, element: Element) -> None:
+        for id_prefix in element.id_prefixes:
+            self.add_prefix(id_prefix)
+
+    def add_prefix(self, ncname: str) -> None:
+        """ Add a prefix to the list of prefixes to emit
+
+        @param ncname: name to add
+        """
+        if ncname not in self.namespaces:
+            self.logger.warning(f"Unrecognized prefix: {ncname}")
+            self.namespaces[ncname] = f"http://example.org/UNKNOWN/{ncname}/"
+        self.emit_prefixes.add(ncname)
+
 
 def shared_arguments(g: Type[Generator]) -> Callable[[Command], Command]:
     _LOG_LEVEL_STRINGS = ['CRITICAL', 'ERROR', 'WARNING', 'INFO', 'DEBUG']

diff --git a/tests/test_prefixes/input/prefixtest.yaml b/tests/test_prefixes/input/prefixtest.yaml
index facfb560..5fcf384b 100644
--- a/tests/test_prefixes/input/prefixtest.yaml
+++ b/tests/test_prefixes/input/prefixtest.yaml
@@ -45,6 +45,7 @@ classes:
   Class:
     class_uri: owl:Class
 
+
 slots:
 
   id:
diff --git a/tests/test_prefixes/output/prefixtest.prefixmap.json b/tests/test_prefixes/output/prefixtest.prefixmap.json
index f35e1783..2b519f98 100644
--- a/tests/test_prefixes/output/prefixtest.prefixmap.json
+++ b/tests/test_prefixes/output/prefixtest.prefixmap.json
@@ -1,7 +1,10 @@
 {
+   "BFO": "http://purl.obolibrary.org/obo/BFO_",
    "CL": "http://purl.obolibrary.org/obo/CL_",
    "GO": "http://purl.obolibrary.org/obo/GO_",
+   "PR": "http://purl.obolibrary.org/obo/PR_",
    "SIO": "http://semanticscience.org/resource/SIO_",
+   "SO": "http://purl.obolibrary.org/obo/SO_",
    "biolink": "https://w3id.org/biolink/",
    "dbont": "http://dbpedia.org/ontology/",
    "dce": "http://purl.org/dc/elements/1.1/",
@@ -10,6 +13,8 @@
    "owl": "http://www.w3.org/2002/07/owl#",
    "pav": "http://purl.org/pav/",
    "prefixtest": "https://w3id.org/linkml/tests/prefixtest/",
+   "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
+   "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
    "sdo": "http://schema.org/",
    "wd": "https://www.wikidata.org/wiki/",
    "Class": {
diff --git a/tests/test_prefixes/test_prefixes.py b/tests/test_prefixes/test_prefixes.py
index 021c7f8f..743f620c 100644
--- a/tests/test_prefixes/test_prefixes.py
+++ b/tests/test_prefixes/test_prefixes.py
@@ -47,10 +47,12 @@ class PrefixTestCase(unittest.TestCase):
         with open(PM_OUTPUT, 'w') as stream:
             stream.write(out)
         expected = {
-            # TODO: rdf, rdfs, BFO, ... should all be here
+            "BFO": "http://purl.obolibrary.org/obo/BFO_",
             "CL": "http://purl.obolibrary.org/obo/CL_",
             "GO": "http://purl.obolibrary.org/obo/GO_",
+            "PR": "http://purl.obolibrary.org/obo/PR_",
             "SIO": "http://semanticscience.org/resource/SIO_",
+            "SO": "http://purl.obolibrary.org/obo/SO_",
             "biolink": "https://w3id.org/biolink/",
             "dbont": "http://dbpedia.org/ontology/",
             "dce": "http://purl.org/dc/elements/1.1/",
@@ -59,6 +61,8 @@ class PrefixTestCase(unittest.TestCase):
             "owl": "http://www.w3.org/2002/07/owl#",
             "pav": "http://purl.org/pav/",
             "prefixtest": "https://w3id.org/linkml/tests/prefixtest/",
+            "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
+            "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
             "sdo": "http://schema.org/",
             "wd": "https://www.wikidata.org/wiki/"
         }

Abstract add_mappings code into common generator superclass
`def add_mappings`  is duplicated across different generators with drift between the code, causing a variety of subtle issues relating to loss of prefix information

See my comment here:

https://github.com/linkml/linkml/issues/192#issuecomment-883537162

The fix is to simply move add_mappings from jsonldcontext gen into the parent, and to remove it from pythongen and prefixmapgen

I hypothesize this will fix #163
tests/test_prefixes/test_prefixes.py::PrefixTestCase::test_prefixmapgen
tests/test_prefixes/test_prefixes.py::PrefixTestCase::test_jsonldcontext