diff --git a/config.m4 b/config.m4
index 18d4bdb..060f84f 100644
--- a/config.m4
+++ b/config.m4
@@ -1,20 +1,68 @@
-PHP_ARG_WITH(phplpsolve55,[lpsolve 5.5]
-[  with-phplpsolve55=[Insert path to lp_solve here]            Include lpsolve Support])
+PHP_ARG_WITH(phplpsolve55, for liblpsolve55,
+[ --with-phplpsolve55=DIR Installation prefix of liblpsolve55.
+                          If DIR is not specified, use the system library.])
 
 if test $PHP_PHPLPSOLVE55 != "no"; then
-  if test -f "$PHP_PHPLPSOLVE55/lp_lib.h"; then
-    PHP_CHECK_LIBRARY(lpsolve55, make_lp,,[AC_MSG_ERROR([Invalid phplpsolve55 library, make_lp() not found])],-L/usr/lib)
-  else
-    dnl This will cancel configuration if the required headers aren't found
-    AC_MSG_ERROR([lp_lib.h not found])
+  EXTRA_LIBS="-lm"
+  AC_CHECK_LIB(dl, dlopen, [
+    EXTRA_LIBS="$EXTRA_LIBS -ldl"
+    PHP_ADD_LIBRARY(dl, 1, PHPLPSOLVE55_SHARED_LIBADD)
+  ])
+  AC_CHECK_LIB(colamd, colamd, [
+    EXTRA_LIBS="$EXTRA_LIBS -lcolamd"
+  ])
+  dnl Find the header file:
+  AC_MSG_CHECKING([for lp_lib.h])
+  for i in $PHP_PHPLPSOLVE55 /usr/include/lpsolve /usr/local/include/lpsolve; do
+    if test -r "$i/lp_lib.h"; then
+      LIBLPSOLVE_INCDIR="$i"
+      AC_MSG_RESULT($i)
+      break
+    fi
+  done
+
+  if test -z "$LIBLPSOLVE_INCDIR"; then
+    AC_MSG_RESULT([not found])
+    AC_MSG_ERROR([Could not find lp_lib.h])
   fi
 
-  PHP_ADD_LIBRARY_WITH_PATH(lpsolve55, /usr/local/lib, PHPLPSOLVE55_SHARED_LIBADD)
-  PHP_ADD_INCLUDE($PHP_PHPLPSOLVE55)
-  AC_MSG_RESULT([lpsolve in $PHP_PHPLPSOLVE55])
-  AC_DEFINE(PHP,1,[liblpsolve55 found and included])
+  dnl Find the shared library:
+  LDFLAGS="-Wl,--no-as-needed"
+  for i in /usr/local/lib /usr/lib /lib; do
+    for j in lpsolve55_pic lpsolve55; do
+      if test -r "$i/lib$j.so"; then
+        PHP_CHECK_LIBRARY($j, make_lp,[
+            PHP_ADD_LIBRARY_WITH_PATH($j, $i, PHPLPSOLVE55_SHARED_LIBADD)
+            PHP_ADD_INCLUDE($LIBLPSOLVE_INCDIR)
+            LIBLPSOLVE_LIBDIR="$i"
+            break 2
+          ],[
+            continue
+          ],[
+            -L$i $EXTRA_LIBS
+          ]
+        )
+      fi
+    done
+  done
+
+  for i in lpsolve55_pic lpsolve55; do
+    if test -z "$LIBLPSOLVE_LIBDIR"; then
+    PHP_CHECK_LIBRARY($i, make_lp,[
+          PHP_ADD_LIBRARY($i, 1, PHPLPSOLVE55_SHARED_LIBADD)
+          PHP_ADD_INCLUDE($LIBLPSOLVE_INCDIR)
+          LIBLPSOLVE_LIBDIR="$i"
+        ],[
+          AC_MSG_ERROR([Could not find liblpsolve55.so or symbol make_lp.  Check version and config.log for more information.])
+        ],[
+          $EXTRA_LIBS
+        ]
+      )
+    fi
+  done
+  LDFLAGS=""
   AC_DEFINE(DEMO,1,[DEMO code in lpsolve])
-  PHP_NEW_EXTENSION(phplpsolve55, PHPmod.c hash.c lpsolve.c, $ext_shared)
+  AC_DEFINE(PHP,1,[liblpsolve55 found and included])
   PHP_SUBST(PHPLPSOLVE55_SHARED_LIBADD)
-fi
-
+  PHP_NEW_EXTENSION(phplpsolve55, PHPmod.c hash.c lpsolve.c, $ext_shared)
+fi
\ No newline at end of file
diff --git a/hash.c b/hash.c
index b990f3f..6296b98 100644
--- a/hash.c
+++ b/hash.c
@@ -8,7 +8,6 @@
 
 #include <sys/types.h>
 #include <stdlib.h>
-#include <malloc.h>
 #include <string.h>
 
 #include "hash.h"
diff --git a/hash.h b/hash.h
index b783068..caa823c 100644
--- a/hash.h
+++ b/hash.h
@@ -23,13 +23,14 @@ typedef struct _hashtable
 extern "C" {
 #endif
 
-hashtable *create_hash_table(int size, int base);
-void      free_hash_table(hashtable *ht);
-hashelem  *findhash(const char *name, hashtable *ht);
-hashelem  *puthash(const char *name, int index, hashelem **list, hashtable *ht);
-void      drophash(const char *name, hashelem **list, hashtable *ht);
-void      free_hash_item(hashelem **hp);
-hashtable *copy_hash_table(hashtable *ht, hashelem **list, int newsize);
+static inline hashtable *create_hash_table(int size, int base);
+static inline void      free_hash_table(hashtable *ht);
+static inline hashelem  *findhash(const char *name, hashtable *ht);
+static inline hashelem  *puthash(const char *name, int index, hashelem **list, hashtable *ht);
+static inline void      drophash(const char *name, hashelem **list, hashtable *ht);
+static inline void      free_hash_item(hashelem **hp);
+static inline hashtable *copy_hash_table(hashtable *ht, hashelem **list, int newsize);
+static inline int       hashval(const char *string, int size);
 
 #ifdef __cplusplus
  }
diff --git a/tests/01-empty.phpt b/tests/01-empty.phpt
new file mode 100644
index 0000000..a68b0ba
--- /dev/null
+++ b/tests/01-empty.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Empty test
+--SKIPIF--
+<?php
+if(!extension_loaded("lpsolve")) echo 'skip';
+?>
+--FILE--
+<?php
+var_dump(lpsolve('make_lp', 0, 0));
+?>
+--EXPECT--
+int(0)
\ No newline at end of file