diff --git a/icu4c/source/common/ucnv_set.c b/icu4c/source/common/ucnv_set.c
index cbfd9632d8c..c192ea4f869 100644
--- a/icu4c/source/common/ucnv_set.c
+++ b/icu4c/source/common/ucnv_set.c
@@ -24,6 +24,8 @@
 #include "ucnv_bld.h"
 #include "uset_imp.h"
 
+#if !UCONFIG_NO_CONVERSION
+
 U_CAPI void U_EXPORT2
 ucnv_getUnicodeSet(const UConverter *cnv,
                    USet *setFillIn,
@@ -60,3 +62,5 @@ ucnv_getUnicodeSet(const UConverter *cnv,
         cnv->sharedData->impl->getUnicodeSet(cnv, &sa, whichSet, pErrorCode);
     }
 }
+
+#endif
diff --git a/icu4c/source/common/unicode/uconfig.h b/icu4c/source/common/unicode/uconfig.h
index f7a74a8635f..e28df941f26 100644
--- a/icu4c/source/common/unicode/uconfig.h
+++ b/icu4c/source/common/unicode/uconfig.h
@@ -60,6 +60,7 @@
 
 /**
  * \def UCONFIG_NO_CONVERSION
+ * ICU will not completely build with this switch turned on.
  * This switch turns off all converters.
  *
  * @draft ICU 3.2