diff --git a/cinelerra-5.1/configure.ac b/cinelerra-5.1/configure.ac
index f10af67..7e9e5f1 100644
--- a/cinelerra-5.1/configure.ac
+++ b/cinelerra-5.1/configure.ac
@@ -8,7 +8,7 @@ AC_LANG_CPLUSPLUS
 AC_LANG_C
 AC_PROG_CXX
 
-CFG_CFLAGS+=" -fno-omit-frame-pointer -fno-math-errno -fno-signed-zeros"
+CFG_CFLAGS+=" -std=c++11 -fno-omit-frame-pointer -fno-math-errno -fno-signed-zeros"
 CFG_CFLAGS+=" -pthread -Wall"
 # misguided pedantic warnings
 #  this is extra work, not a gain...
@@ -239,14 +239,6 @@ PKG_3RD([giflib],[yes],
     libutil.a ],
   [ . ])
 
-PKG_3RD([ilmbase],[auto],
-  [ilmbase-2.2.1],
-  [ Iex/.libs/libIex.a \
-    IexMath/.libs/libIexMath.a \
-    Half/.libs/libHalf.a \
-    Imath/.libs/libImath.a \
-    IlmThread/.libs/libIlmThread.a ],
-  [ Iex Half Imath config IlmThread ])
 
 PKG_DEF([ladspa], [ladspa-0.4.17], [], [])
 
@@ -338,10 +330,15 @@ PKG_3RD([mjpegtools],[yes],
   [ .  lavtools utils ])
 
 PKG_3RD([openexr],[auto],
-  [openexr-2.2.1],
-  [ IlmImf/.libs/libIlmImf.a \
-    IlmImfUtil/.libs/libIlmImfUtil.a ],
-  [ IlmImf config ])
+  [openexr-2.4.1],
+    [ IlmBase/Iex/.libs/libIex.a \
+    IlmBase/IexMath/.libs/libIexMath.a \
+    IlmBase/Half/.libs/libHalf.a \
+    IlmBase/Imath/.libs/libImath.a \
+    IlmBase/IlmThread/.libs/libIlmThread.a 
+    OpenEXR/IlmImf/.libs/libIlmImf.a \
+    OpenEXR/IlmImfUtil/.libs/libIlmImfUtil.a ],
+  [ Iex Half Imath IlmThread IlmImf config usr/include/OpenEXR ])
 
 #PKG_3RD([festival],[no],
 #  [festival],