diff --git a/Makefile b/Makefile
index 889a78c9..d112be6a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,3 @@
-# Default FLAGS, (can be overridden by user such as "make CFLAGS=-g")
-CFLAGS=-O2
-
 WARN_CXXFLAGS=-Wall -Wextra -Wwrite-strings -Wswitch-enum
 WARN_CFLAGS=$(WARN_CXXFLAGS) -Wmissing-declarations
 
diff --git a/configure b/configure
index 488b3bd7..ff8baa5e 100755
--- a/configure
+++ b/configure
@@ -2,6 +2,8 @@
 
 CC=${CC:-gcc}
 CXX=${CXX:-g++}
+CFLAGS=${CFLAGS:--O2}
+CXXFLAGS=${CXXFLAGS:-\$(CFLAGS)}
 
 # defaults
 PREFIX=/usr/local
@@ -195,6 +197,12 @@ CC = ${CC}
 # The C++ compiler to use
 CXX = ${CXX}
 
+# Default FLAGS for C compiler (can be overridden by user such as "make CFLAGS=-g")
+CFLAGS = ${CFLAGS}
+
+# Default FLAGS for C++ compiler (can be overridden by user such as "make CXXFLAGS=-g")
+CXXFLAGS = ${CXXFLAGS}
+
 # The prefix to which notmuch should be installed
 prefix = ${PREFIX}