diff --git a/CTestCustom.cmake.in b/CTestCustom.cmake.in
index 710681cce..48dd3debc 100644
--- a/CTestCustom.cmake.in
+++ b/CTestCustom.cmake.in
@@ -67,6 +67,7 @@ list(APPEND CTEST_CUSTOM_WARNING_EXCEPTION
   "cm(StringCommand|CTestTestHandler)\\.cxx.*warning.*rand.*may return deterministic values"
   "cm(StringCommand|CTestTestHandler)\\.cxx.*warning.*rand.*isn.*t random" # we do not do crypto
   "cm(StringCommand|CTestTestHandler)\\.cxx.*warning.*srand.*seed choices are.*poor" # we do not do crypto
+  "IPA warning: function.*multiply defined in"
 
   # Ignore clang's summary warning, assuming prior text has matched some
   # other warning expression:
diff --git a/CompileFlags.cmake b/CompileFlags.cmake
index 382787cfb..c875e6f1f 100644
--- a/CompileFlags.cmake
+++ b/CompileFlags.cmake
@@ -71,6 +71,13 @@ if (CMAKE_CXX_COMPILER_ID STREQUAL SunPro)
   endif()
 endif()
 
+foreach(lang C CXX)
+  # Suppress warnings from PGI compiler.
+  if (CMAKE_${lang}_COMPILER_ID STREQUAL "PGI")
+    set(CMAKE_${lang}_FLAGS "${CMAKE_${lang}_FLAGS} -w")
+  endif()
+endforeach()
+
 # use the ansi CXX compile flag for building cmake
 if (CMAKE_ANSI_CXXFLAGS)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_ANSI_CXXFLAGS}")