diff --git a/icu4c/source/i18n/rbnf.cpp b/icu4c/source/i18n/rbnf.cpp
index f05c549d58..b046887ab2 100644
--- a/icu4c/source/i18n/rbnf.cpp
+++ b/icu4c/source/i18n/rbnf.cpp
@@ -316,13 +316,33 @@ public:
     
 private:
     
-    void inc(void) { ++p; ch = 0xffff; }
-    UBool checkInc(UChar c) { if (p < e && (ch == c || *p == c)) { inc(); return TRUE; } return FALSE; }
-    UBool check(UChar c) { return p < e && (ch == c || *p == c); }
-    void skipWhitespace(void) { while (p < e && PatternProps::isWhiteSpace(ch != 0xffff ? ch : *p)) inc();}
-    UBool inList(UChar c, const UChar* list) const {
-        if (*list == SPACE && PatternProps::isWhiteSpace(c)) return TRUE;
-        while (*list && *list != c) ++list; return *list == c;
+    inline void inc(void) {
+        ++p;
+        ch = 0xffff;
+    }
+    inline UBool checkInc(UChar c) {
+        if (p < e && (ch == c || *p == c)) {
+            inc();
+            return TRUE;
+        }
+        return FALSE;
+    }
+    inline UBool check(UChar c) {
+        return p < e && (ch == c || *p == c);
+    }
+    inline void skipWhitespace(void) {
+        while (p < e && PatternProps::isWhiteSpace(ch != 0xffff ? ch : *p)) {
+            inc();
+        }
+    }
+    inline UBool inList(UChar c, const UChar* list) const {
+        if (*list == SPACE && PatternProps::isWhiteSpace(c)) {
+            return TRUE;
+        }
+        while (*list && *list != c) {
+            ++list;
+        }
+        return *list == c;
     }
     void parseError(const char* msg);