diff --git a/icu4c/source/common/unicode/utypes.h b/icu4c/source/common/unicode/utypes.h
index b341cb47d4a..5db17d7498d 100644
--- a/icu4c/source/common/unicode/utypes.h
+++ b/icu4c/source/common/unicode/utypes.h
@@ -171,7 +171,7 @@
 #if defined(OS390) && (__COMPILER_VER__ < 0x41020000) && defined(XP_CPLUSPLUS)
 #    define U_CALLCONV __cdecl
 #else
-#    define U_CALLCONV 
+#    define U_CALLCONV U_EXPORT2
 #endif
 
 /**
diff --git a/icu4c/source/common/uvector.cpp b/icu4c/source/common/uvector.cpp
index 5ff1ff9c466..01c23e0ede9 100644
--- a/icu4c/source/common/uvector.cpp
+++ b/icu4c/source/common/uvector.cpp
@@ -88,7 +88,7 @@ UVector::~UVector() {
  * Assign this object to another (make this a copy of 'other').
  * Use the 'assign' function to assign each element.
  */
-void UVector::assign(const UVector& other, UTokenAssigner assign, UErrorCode &ec) {
+void UVector::assign(const UVector& other, UTokenAssigner *assign, UErrorCode &ec) {
     if (ensureCapacity(other.count, ec)) {
         setSize(other.count);
         for (int32_t i=0; i<other.count; ++i) {
@@ -421,7 +421,7 @@ void* UVector::orphanElementAt(int32_t index) {
  * as defined by 'compare'.  The current elements are assumed to
  * be sorted already.
  */
-void UVector::sortedInsert(void* obj, USortComparator compare, UErrorCode& ec) {
+void UVector::sortedInsert(void* obj, USortComparator *compare, UErrorCode& ec) {
     UHashTok tok;
     tok.pointer = obj;
     sortedInsert(tok, compare, ec);
@@ -432,14 +432,14 @@ void UVector::sortedInsert(void* obj, USortComparator compare, UErrorCode& ec) {
  * as defined by 'compare'.  The current elements are assumed to
  * be sorted already.
  */
-void UVector::sortedInsert(int32_t obj, USortComparator compare, UErrorCode& ec) {
+void UVector::sortedInsert(int32_t obj, USortComparator *compare, UErrorCode& ec) {
     UHashTok tok;
     tok.integer = obj;
     sortedInsert(tok, compare, ec);
 }
 
 // ASSUME elements[] IS CURRENTLY SORTED
-void UVector::sortedInsert(UHashTok tok, USortComparator compare, UErrorCode& ec) {
+void UVector::sortedInsert(UHashTok tok, USortComparator *compare, UErrorCode& ec) {
     // Perform a binary search for the location to insert tok at.  Tok
     // will be inserted between two elements a and b such that a <=
     // tok && tok < b, where there is a 'virtual' elements[-1] always
diff --git a/icu4c/source/common/uvector.h b/icu4c/source/common/uvector.h
index a026bf0155c..ba310a7662b 100644
--- a/icu4c/source/common/uvector.h
+++ b/icu4c/source/common/uvector.h
@@ -25,8 +25,8 @@ U_NAMESPACE_BEGIN
  * @return 0 if the two tokens are equal, -1 if tok1 is < tok2, or
  * +1 if tok1 is > tok2.
  */
-typedef int8_t (U_EXPORT2 * U_CALLCONV USortComparator)(UHashTok tok1,
-                                                        UHashTok tok2);
+typedef int8_t U_CALLCONV USortComparator(UHashTok tok1,
+                                          UHashTok tok2);
 
 /**
  * A token assignment function.  It may copy an integer, copy
@@ -34,8 +34,8 @@ typedef int8_t (U_EXPORT2 * U_CALLCONV USortComparator)(UHashTok tok1,
  * @param dst The token to be assigned to
  * @param src The token to assign from
  */
-typedef void (U_EXPORT2 * U_CALLCONV UTokenAssigner)(UHashTok dst,
-                                                     UHashTok src);
+typedef void U_CALLCONV UTokenAssigner(UHashTok dst,
+                                       UHashTok src);
 
 /**
  * <p>Ultralightweight C++ implementation of a <tt>void*</tt> vector
@@ -121,7 +121,7 @@ public:
      * Assign this object to another (make this a copy of 'other').
      * Use the 'assign' function to assign each element.
      */
-    void assign(const UVector& other, UTokenAssigner assign, UErrorCode &ec);
+    void assign(const UVector& other, UTokenAssigner *assign, UErrorCode &ec);
 
     /**
      * Compare this vector with another.  They will be considered
@@ -236,14 +236,14 @@ public:
      * as defined by 'compare'.  The current elements are assumed to
      * be sorted already.
      */
-    void sortedInsert(void* obj, USortComparator compare, UErrorCode& ec);
+    void sortedInsert(void* obj, USortComparator *compare, UErrorCode& ec);
 
     /**
      * Insert the given integer into this vector at its sorted position
      * as defined by 'compare'.  The current elements are assumed to
      * be sorted already.
      */
-    void sortedInsert(int32_t obj, USortComparator compare, UErrorCode& ec);
+    void sortedInsert(int32_t obj, USortComparator *compare, UErrorCode& ec);
 
     /**
      * ICU "poor man's RTTI", returns a UClassID for the actual class.
@@ -264,7 +264,7 @@ private:
 
     int32_t indexOf(UHashTok key, int32_t startIndex = 0, int8_t hint = 0) const;
 
-    void sortedInsert(UHashTok tok, USortComparator compare, UErrorCode& ec);
+    void sortedInsert(UHashTok tok, USortComparator *compare, UErrorCode& ec);
 
     // Disallow
     UVector(const UVector&);