diff --git a/configure.ac b/configure.ac
index ac56f88..a5c6640 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@ AC_PREREQ(2.52)
 
 m4_define([PKG_VERSION_MAJOR], [3])
 m4_define([PKG_VERSION_MINOR], [7])
-m4_define([PKG_VERSION_PATCH], [5])
+m4_define([PKG_VERSION_PATCH], [6])
 
 # Bump if the ABI (not API) changed in a backwards-incompatible manner
 m4_define([PKG_VERSION_ABI], [3])
@@ -61,8 +61,7 @@ AC_TYPE_SIZE_T
 # Checks for library functions.
 AC_FUNC_ERROR_AT_LINE
 
-AC_CHECK_DECLS([fread_unlocked, fwrite_unlocked, fgetc_unlocked, \
-fputc_unlocked, fputs_unlocked])
+AC_CHECK_DECLS([fread_unlocked, fwrite_unlocked, fgetc_unlocked, fputc_unlocked, fputs_unlocked, fmemopen])
 
 AC_CHECK_FUNCS([setlocale strdup getopt_long])
 
diff --git a/lttoolbox/input_file.cc b/lttoolbox/input_file.cc
index b10d418..f296927 100644
--- a/lttoolbox/input_file.cc
+++ b/lttoolbox/input_file.cc
@@ -44,13 +44,15 @@ InputFile::open(const char* fname)
   return (infile != nullptr);
 }
 
+#if HAVE_DECL_FMEMOPEN
 bool
 InputFile::open_in_memory(char *input_buffer)
 {
   close();
   infile = fmemopen(input_buffer, strlen(input_buffer), "rb");
-  return (infile != nullptr);  
+  return (infile != nullptr);
 }
+#endif
 
 void
 InputFile::open_or_exit(const char* fname)
diff --git a/lttoolbox/input_file.h b/lttoolbox/input_file.h
index 7925ad4..2a5fb72 100644
--- a/lttoolbox/input_file.h
+++ b/lttoolbox/input_file.h
@@ -34,7 +34,9 @@ class InputFile
   InputFile();
   ~InputFile();
   bool open(const char* fname = nullptr);
+#if HAVE_DECL_FMEMOPEN
   bool open_in_memory(char* input_buffer);
+#endif
   void open_or_exit(const char* fname = nullptr);
   void close();
   void wrap(FILE* newinfile);