diff --git a/icu4c/source/i18n/translit.cpp b/icu4c/source/i18n/translit.cpp
index 12cb93e8757..19e4284b179 100644
--- a/icu4c/source/i18n/translit.cpp
+++ b/icu4c/source/i18n/translit.cpp
@@ -14,6 +14,7 @@
 #include "rbt_data.h"
 #include "rbt_pars.h"
 #include "transreg.h"
+#include "ucln_in.h"
 #include "unicode/cpdtrans.h"
 #include "unicode/hangjamo.h"
 #include "unicode/hextouni.h"
@@ -1438,28 +1439,21 @@ void Transliterator::initializeRegistry(void) {
     registry->put(new UnicodeNameTransliterator(), TRUE);
     registry->put(new NameUnicodeTransliterator(), TRUE);
     NormalizationTransliterator::registerIDs();
+    ucln_i18n_registerCleanup();
 }
 
 // Defined in ucln_in.h:
 
-/**
- * Cleanup function for transliterator component; delegates to
- * Transliterator::cleanupRegistry().
- */
-U_CFUNC UBool transliterator_cleanup(void) {
-    Transliterator::cleanupRegistry();
-    return TRUE;
-}
-
 /**
  * Release all static memory held by transliterator.  This will
  * necessarily invalidate any rule-based transliterators held by the
  * user, because RBTs hold pointers to common data objects.
- */ 
-void Transliterator::cleanupRegistry() {
-    Mutex lock(&registryMutex);
+ */
+U_CFUNC UBool transliterator_cleanup(void) {
     delete registry;
     registry = 0;
+    umtx_destroy(&registryMutex);
+    return TRUE;
 }
 
 //eof
diff --git a/icu4c/source/i18n/ucln_in.c b/icu4c/source/i18n/ucln_in.c
index c50a4be0c58..8e94c8985ee 100644
--- a/icu4c/source/i18n/ucln_in.c
+++ b/icu4c/source/i18n/ucln_in.c
@@ -19,10 +19,11 @@
 
 static UBool i18n_cleanup(void)
 {
-    ucol_bld_cleanup();
-    ucol_cleanup();
-    timeZone_cleanup();
     transliterator_cleanup();
+    unicodeset_cleanup();
+    timeZone_cleanup();
+    ucol_cleanup();
+    ucol_bld_cleanup();
     return TRUE;
 }
 
diff --git a/icu4c/source/i18n/ucln_in.h b/icu4c/source/i18n/ucln_in.h
index 58f1fa6d6e1..9ecd837cdbe 100644
--- a/icu4c/source/i18n/ucln_in.h
+++ b/icu4c/source/i18n/ucln_in.h
@@ -22,12 +22,16 @@
 /* Main library cleanup function. */
 U_CFUNC void ucln_i18n_registerCleanup(void);
 
+/* See common/ucln.h for details on adding a cleanup function. */
+
+U_CFUNC UBool transliterator_cleanup(void);
+
+U_CFUNC UBool unicodeset_cleanup(void);
+
+U_CFUNC UBool timeZone_cleanup(void);
+
 U_CFUNC UBool ucol_cleanup(void);
 
 U_CFUNC UBool ucol_bld_cleanup(void);
 
-U_CFUNC UBool timeZone_cleanup(void);
-
-U_CFUNC UBool transliterator_cleanup(void);
-
 #endif
diff --git a/icu4c/source/i18n/unicode/translit.h b/icu4c/source/i18n/unicode/translit.h
index a86cc83a62c..da2634f7199 100644
--- a/icu4c/source/i18n/unicode/translit.h
+++ b/icu4c/source/i18n/unicode/translit.h
@@ -925,9 +925,6 @@ protected:
 
 private:
     static void initializeRegistry(void);
-
-    friend UBool transliterator_cleanup();
-    static void cleanupRegistry(void);
 };
 
 inline int32_t Transliterator::getMaximumContextLength(void) const {
diff --git a/icu4c/source/i18n/unicode/uniset.h b/icu4c/source/i18n/unicode/uniset.h
index 9b0ed7b242b..3e39205e9c1 100644
--- a/icu4c/source/i18n/unicode/uniset.h
+++ b/icu4c/source/i18n/unicode/uniset.h
@@ -265,13 +265,6 @@ class U_I18N_API UnicodeSet : public UnicodeFilter {
      */
     UnicodeString pat;
 
-    /**
-     * A cache mapping character category integers, as returned by
-     * Unicode::getType(), to pairs strings.  Entries are initially
-     * zero length and are filled in on demand.
-     */
-    static UnicodeSet* CATEGORY_CACHE;
-
 public:
 
     /**
diff --git a/icu4c/source/i18n/uniset.cpp b/icu4c/source/i18n/uniset.cpp
index d53a28f6479..9e7adcaca30 100644
--- a/icu4c/source/i18n/uniset.cpp
+++ b/icu4c/source/i18n/uniset.cpp
@@ -14,6 +14,8 @@
 #include "symtable.h"
 #include "cmemory.h"
 #include "rbt_rule.h"
+#include "umutex.h"
+#include "ucln_in.h"
 
 // HIGH_VALUE > all valid values. 110000 for codepoints
 #define UNICODESET_HIGH 0x0110000
@@ -92,8 +94,7 @@ static const UChar CATEGORY_NAMES[] = {
  * Unicode::getType(), to pairs strings.  Entries are initially
  * zero length and are filled in on demand.
  */
-UnicodeSet _CATEGORY_CACHE[Unicode::GENERAL_TYPES_COUNT];
-UnicodeSet* UnicodeSet::CATEGORY_CACHE = _CATEGORY_CACHE;
+static UnicodeSet* CATEGORY_CACHE = NULL;
 
 /**
  * Delimiter string used in patterns to close a category reference:
@@ -102,6 +103,18 @@ UnicodeSet* UnicodeSet::CATEGORY_CACHE = _CATEGORY_CACHE;
 static const UChar CATEGORY_CLOSE[] = {COLON, SET_CLOSE, 0x0000}; /* ":]" */
 
 
+/**
+ * Cleanup function for transliterator component; delegates to
+ * Transliterator::cleanupRegistry().
+ */
+U_CFUNC UBool unicodeset_cleanup(void) {
+    if (CATEGORY_CACHE) {
+        delete []CATEGORY_CACHE;
+        CATEGORY_CACHE = NULL;
+    }
+    return TRUE;
+}
+
 //----------------------------------------------------------------
 // Constructors &c
 //----------------------------------------------------------------
@@ -1366,6 +1379,14 @@ const UnicodeSet& UnicodeSet::getCategorySet(int8_t cat) {
     // In order to tell what cache entries are empty, we assume
     // every category specifies at least one character.  Thus
     // sets in the cache that are empty are uninitialized.
+    if (CATEGORY_CACHE == NULL) {
+        umtx_lock(NULL);
+        if (CATEGORY_CACHE == NULL) {
+            CATEGORY_CACHE = new UnicodeSet[Unicode::GENERAL_TYPES_COUNT];
+            ucln_i18n_registerCleanup();
+        }
+        umtx_unlock(NULL);
+    }
     if (CATEGORY_CACHE[cat].isEmpty()) {
         // Walk through all Unicode characters, noting the start
         // and end of each range for which Character.getType(c)