diff --git a/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go b/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
index e725b5cfd30..1e7fb794e95 100644
--- a/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
+++ b/staging/src/k8s.io/code-generator/cmd/conversion-gen/generators/conversion.go
@@ -812,17 +812,23 @@ func (g *genConversion) doMap(inType, outType *types.Type, sw *generator.Snippet
 				sw.Do("$.|raw$(val)\n", outType.Elem)
 			}
 		} else {
-			sw.Do("newVal := new($.|raw$)\n", outType.Elem)
+			conversionExists := true
 			if function, ok := g.preexists(inType.Elem, outType.Elem); ok {
+				sw.Do("newVal := new($.|raw$)\n", outType.Elem)
 				sw.Do("if err := $.|raw$(&val, newVal, s); err != nil {\n", function)
 			} else if g.convertibleOnlyWithinPackage(inType.Elem, outType.Elem) {
+				sw.Do("newVal := new($.|raw$)\n", outType.Elem)
 				sw.Do("if err := "+nameTmpl+"(&val, newVal, s); err != nil {\n", argsFromType(inType.Elem, outType.Elem))
 			} else {
-				sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-				sw.Do("if err := s.Convert(&val, newVal, 0); err != nil {\n", nil)
+				args := argsFromType(inType.Elem, outType.Elem)
+				sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+				sw.Do("compileErrorOnMissingConversion()\n", nil)
+				conversionExists = false
+			}
+			if conversionExists {
+				sw.Do("return err\n", nil)
+				sw.Do("}\n", nil)
 			}
-			sw.Do("return err\n", nil)
-			sw.Do("}\n", nil)
 			if inType.Key == outType.Key {
 				sw.Do("(*out)[key] = *newVal\n", nil)
 			} else {
@@ -850,21 +856,21 @@ func (g *genConversion) doSlice(inType, outType *types.Type, sw *generator.Snipp
 				sw.Do("(*out)[i] = $.|raw$((*in)[i])\n", outType.Elem)
 			}
 		} else {
+			conversionExists := true
 			if function, ok := g.preexists(inType.Elem, outType.Elem); ok {
 				sw.Do("if err := $.|raw$(&(*in)[i], &(*out)[i], s); err != nil {\n", function)
 			} else if g.convertibleOnlyWithinPackage(inType.Elem, outType.Elem) {
 				sw.Do("if err := "+nameTmpl+"(&(*in)[i], &(*out)[i], s); err != nil {\n", argsFromType(inType.Elem, outType.Elem))
 			} else {
-				// TODO: This triggers on metav1.ObjectMeta <-> metav1.ObjectMeta and
-				// similar because neither package is the target package, and
-				// we really don't know which package will have the conversion
-				// function defined.  This fires on basically every object
-				// conversion outside of pkg/api/v1.
-				sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-				sw.Do("if err := s.Convert(&(*in)[i], &(*out)[i], 0); err != nil {\n", nil)
+				args := argsFromType(inType.Elem, outType.Elem)
+				sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+				sw.Do("compileErrorOnMissingConversion()\n", nil)
+				conversionExists = false
+			}
+			if conversionExists {
+				sw.Do("return err\n", nil)
+				sw.Do("}\n", nil)
 			}
-			sw.Do("return err\n", nil)
-			sw.Do("}\n", nil)
 		}
 		sw.Do("}\n", nil)
 	}
@@ -971,14 +977,19 @@ func (g *genConversion) doStruct(inType, outType *types.Type, sw *generator.Snip
 				sw.Do("out.$.name$ = in.$.name$\n", args)
 				continue
 			}
+			conversionExists := true
 			if g.convertibleOnlyWithinPackage(inMemberType, outMemberType) {
 				sw.Do("if err := "+nameTmpl+"(&in.$.name$, &out.$.name$, s); err != nil {\n", args)
 			} else {
-				sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-				sw.Do("if err := s.Convert(&in.$.name$, &out.$.name$, 0); err != nil {\n", args)
+				args := argsFromType(inMemberType, outMemberType)
+				sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+				sw.Do("compileErrorOnMissingConversion()\n", nil)
+				conversionExists = false
+			}
+			if conversionExists {
+				sw.Do("return err\n", nil)
+				sw.Do("}\n", nil)
 			}
-			sw.Do("return err\n", nil)
-			sw.Do("}\n", nil)
 		case types.Alias:
 			if isDirectlyAssignable(inMemberType, outMemberType) {
 				if inMemberType == outMemberType {
@@ -987,24 +998,34 @@ func (g *genConversion) doStruct(inType, outType *types.Type, sw *generator.Snip
 					sw.Do("out.$.name$ = $.outType|raw$(in.$.name$)\n", args)
 				}
 			} else {
+				conversionExists := true
 				if g.convertibleOnlyWithinPackage(inMemberType, outMemberType) {
 					sw.Do("if err := "+nameTmpl+"(&in.$.name$, &out.$.name$, s); err != nil {\n", args)
 				} else {
-					sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-					sw.Do("if err := s.Convert(&in.$.name$, &out.$.name$, 0); err != nil {\n", args)
+					args := argsFromType(inMemberType, outMemberType)
+					sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+					sw.Do("compileErrorOnMissingConversion()\n", nil)
+					conversionExists = false
+				}
+				if conversionExists {
+					sw.Do("return err\n", nil)
+					sw.Do("}\n", nil)
 				}
-				sw.Do("return err\n", nil)
-				sw.Do("}\n", nil)
 			}
 		default:
+			conversionExists := true
 			if g.convertibleOnlyWithinPackage(inMemberType, outMemberType) {
 				sw.Do("if err := "+nameTmpl+"(&in.$.name$, &out.$.name$, s); err != nil {\n", args)
 			} else {
-				sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-				sw.Do("if err := s.Convert(&in.$.name$, &out.$.name$, 0); err != nil {\n", args)
+				args := argsFromType(inMemberType, outMemberType)
+				sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+				sw.Do("compileErrorOnMissingConversion()\n", nil)
+				conversionExists = false
+			}
+			if conversionExists {
+				sw.Do("return err\n", nil)
+				sw.Do("}\n", nil)
 			}
-			sw.Do("return err\n", nil)
-			sw.Do("}\n", nil)
 		}
 	}
 }
@@ -1033,16 +1054,21 @@ func (g *genConversion) doPointer(inType, outType *types.Type, sw *generator.Sni
 			sw.Do("**out = $.|raw$(**in)\n", outType.Elem)
 		}
 	} else {
+		conversionExists := true
 		if function, ok := g.preexists(inType.Elem, outType.Elem); ok {
 			sw.Do("if err := $.|raw$(*in, *out, s); err != nil {\n", function)
 		} else if g.convertibleOnlyWithinPackage(inType.Elem, outType.Elem) {
 			sw.Do("if err := "+nameTmpl+"(*in, *out, s); err != nil {\n", argsFromType(inType.Elem, outType.Elem))
 		} else {
-			sw.Do("// TODO: Inefficient conversion - can we improve it?\n", nil)
-			sw.Do("if err := s.Convert(*in, *out, 0); err != nil {\n", nil)
+			args := argsFromType(inType.Elem, outType.Elem)
+			sw.Do("// FIXME: Provide conversion function to convert $.inType|raw$ to $.outType|raw$\n", args)
+			sw.Do("compileErrorOnMissingConversion()\n", nil)
+			conversionExists = false
+		}
+		if conversionExists {
+			sw.Do("return err\n", nil)
+			sw.Do("}\n", nil)
 		}
-		sw.Do("return err\n", nil)
-		sw.Do("}\n", nil)
 	}
 }