--- a/intl/locale/nsUConvPropertySearch.cpp
+++ b/intl/locale/nsUConvPropertySearch.cpp
@@ -7,17 +7,17 @@
 #include "nsString.h"
 #include "mozilla/BinarySearch.h"
 
 namespace {
 
 struct PropertyComparator
 {
   const nsCString& mKey;
-  PropertyComparator(const nsCString& aKey) : mKey(aKey) {}
+  explicit PropertyComparator(const nsCString& aKey) : mKey(aKey) {}
   int operator()(const char* (&aProperty)[3]) const {
     return mKey.Compare(aProperty[0]);
   }
 };
 
 }
 
 // static

--- a/intl/unicharutil/nsUnicodeNormalizer.cpp
+++ b/intl/unicharutil/nsUnicodeNormalizer.cpp
@@ -237,17 +237,17 @@ mdn__unicode_iscompositecandidate(uint32
 		return (1);
 }
 
 namespace {
 
 struct SequenceAdaptor
 {
 	const composition* const mSequence;
-	SequenceAdaptor(const composition* aSequence) : mSequence(aSequence) {}
+	explicit SequenceAdaptor(const composition* aSequence) : mSequence(aSequence) {}
 	uint32_t operator[](size_t aIdx) const {
 		return mSequence[aIdx].c2;
 	}
 };
 
 } // namespace
 
 static nsresult