diff --git a/lib/googletest/Makefile.inc b/lib/googletest/Makefile.inc
index 43ebace19a1..b1f7fa81416 100644
--- a/lib/googletest/Makefile.inc
+++ b/lib/googletest/Makefile.inc
@@ -10,3 +10,6 @@ CXXFLAGS+=	${GTESTS_FLAGS}
 
 # Silence warnings about usage of deprecated implicit copy constructors
 CXXWARNFLAGS+=  -Wno-deprecated-copy
+
+# Silence warnings about implicit character conversions in gtest-printers.h
+CXXWARNFLAGS+=	${NO_WCHARACTER_CONVERSION}
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
index 50eb04b9fd1..c5f2c2bb783 100644
--- a/share/mk/bsd.sys.mk
+++ b/share/mk/bsd.sys.mk
@@ -133,6 +133,9 @@ NO_WARRAY_PARAMETER=	-Wno-array-parameter
 NO_WSTRICT_PROTOTYPES=	-Wno-strict-prototypes
 NO_WDEPRECATED_NON_PROTOTYPE=-Wno-deprecated-non-prototype
 .endif
+.if ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 210000
+NO_WCHARACTER_CONVERSION=-Wno-character-conversion
+.endif
 .if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 50200
 NO_WUNUSED_BUT_SET_VARIABLE=-Wno-unused-but-set-variable
 .endif
diff --git a/share/mk/googletest.test.inc.mk b/share/mk/googletest.test.inc.mk
index 9ef5a3ceac0..5f4445e7620 100644
--- a/share/mk/googletest.test.inc.mk
+++ b/share/mk/googletest.test.inc.mk
@@ -10,3 +10,6 @@ GTESTS_CXXFLAGS+= -frtti
 CXXFLAGS+=	-I${DESTDIR}${INCLUDEDIR}/private
 
 NO_WTHREAD_SAFETY=
+
+# Silence warnings about implicit character conversions in gtest-printers.h
+CXXWARNFLAGS+=	${NO_WCHARACTER_CONVERSION}