diff --git a/icu4c/source/common/filteredbrk.cpp b/icu4c/source/common/filteredbrk.cpp
index 249da43f411..5a8f0b0873e 100644
--- a/icu4c/source/common/filteredbrk.cpp
+++ b/icu4c/source/common/filteredbrk.cpp
@@ -135,16 +135,19 @@ static const UChar   kFULLSTOP = 0x002E; // '.'
  */
 class SimpleFilteredSentenceBreakData : public UMemory {
 public:
+  SimpleFilteredSentenceBreakData(UCharsTrie *forwards, UCharsTrie *backwards ) 
+      : fForwardsPartialTrie(forwards), fBackwardsTrie(backwards), refcount(1) { }
+  SimpleFilteredSentenceBreakData *incr() { refcount++;  return this; }
+  SimpleFilteredSentenceBreakData *decr() { if((--refcount) <= 0) delete this; return 0; }
+  virtual ~SimpleFilteredSentenceBreakData();
+
   LocalPointer<UCharsTrie>    fForwardsPartialTrie; //  Has ".a" for "a.M."
   LocalPointer<UCharsTrie>    fBackwardsTrie; //  i.e. ".srM" for Mrs.
   int32_t                     refcount;
-  SimpleFilteredSentenceBreakData(UCharsTrie *forwards, UCharsTrie *backwards ) 
-      : fForwardsPartialTrie(forwards), fBackwardsTrie(backwards), refcount(1) { }
-  virtual ~SimpleFilteredSentenceBreakData() {}
-  SimpleFilteredSentenceBreakData *incr() { refcount++;  return this; }
-  SimpleFilteredSentenceBreakData *decr() { if((--refcount) <= 0) delete this; return 0; }
 };
 
+SimpleFilteredSentenceBreakData::~SimpleFilteredSentenceBreakData() {}
+
 /**
  * Concrete implementation
  */
diff --git a/icu4c/source/i18n/csrsbcs.cpp b/icu4c/source/i18n/csrsbcs.cpp
index f969c271c5d..d346af20bb7 100644
--- a/icu4c/source/i18n/csrsbcs.cpp
+++ b/icu4c/source/i18n/csrsbcs.cpp
@@ -167,6 +167,7 @@ NGramParser_IBM420::NGramParser_IBM420(const int32_t *theNgramList, const uint8_
 	alef = 0x00;
 }
 
+NGramParser_IBM420::~NGramParser_IBM420() {}
 
 int32_t NGramParser_IBM420::isLamAlef(int32_t b)
 {
diff --git a/icu4c/source/i18n/csrsbcs.h b/icu4c/source/i18n/csrsbcs.h
index 935a3e7e289..046da679f52 100644
--- a/icu4c/source/i18n/csrsbcs.h
+++ b/icu4c/source/i18n/csrsbcs.h
@@ -54,14 +54,15 @@ public:
 #if !UCONFIG_ONLY_HTML_CONVERSION
 class NGramParser_IBM420 : public NGramParser
 {
-private:
-	int32_t alef;
-	int32_t isLamAlef(int32_t b);
-	int32_t nextByte(InputText *det);
-	void parseCharacters(InputText *det);
-
 public:
     NGramParser_IBM420(const int32_t *theNgramList, const uint8_t *theCharMap);
+    ~NGramParser_IBM420();
+
+private:
+    int32_t alef;
+    int32_t isLamAlef(int32_t b);
+    int32_t nextByte(InputText *det);
+    void parseCharacters(InputText *det);
 };
 #endif
 
diff --git a/icu4c/source/i18n/valueformatter.cpp b/icu4c/source/i18n/valueformatter.cpp
index 71ade13eb8f..d7870d1041d 100644
--- a/icu4c/source/i18n/valueformatter.cpp
+++ b/icu4c/source/i18n/valueformatter.cpp
@@ -24,6 +24,8 @@
 
 U_NAMESPACE_BEGIN
 
+ValueFormatter::~ValueFormatter() {}
+
 VisibleDigitsWithExponent &
 ValueFormatter::toVisibleDigitsWithExponent(
         int64_t value,
diff --git a/icu4c/source/i18n/valueformatter.h b/icu4c/source/i18n/valueformatter.h
index 4370876730f..e985edd390e 100644
--- a/icu4c/source/i18n/valueformatter.h
+++ b/icu4c/source/i18n/valueformatter.h
@@ -45,6 +45,8 @@ public:
     ValueFormatter() : fType(kFormatTypeCount) {
     }
 
+    virtual ~ValueFormatter();
+
     /**
      * This function is here only to support the protected round() method
      * in DecimalFormat. It serves no ther purpose than that.