diff --git a/auto/lib/make b/auto/lib/make
index 7acae50..2c2d232 100644
--- a/auto/lib/make
+++ b/auto/lib/make
@@ -1,12 +1,12 @@
 
-if [ $PCRE != NONE -a $PCRE != NO ]; then
+if [ $PCRE != NONE -a $PCRE != NO -a $PCRE != YES ]; then
     . auto/lib/pcre/make
 fi
 
-if [ $MD5 != NONE -a $MD5 != NO ]; then
+if [ $MD5 != NONE -a $MD5 != NO -a $MD5 != YES ]; then
     . auto/lib/md5/make
 fi
 
-if [ $ZLIB != NONE -a $ZLIB != NO ]; then
+if [ $ZLIB != NONE -a $ZLIB != NO -a $ZLIB != YES ]; then
     . auto/lib/zlib/make
 fi
diff --git a/auto/lib/md5/conf b/auto/lib/md5/conf
index 8871038..3fc1af6 100644
--- a/auto/lib/md5/conf
+++ b/auto/lib/md5/conf
@@ -41,16 +41,17 @@
 else
 
     if [ $PLATFORM != win32 ]; then
-            MD5=NO
+        MD5=NO
+        ngx_lib_cflags=
 
-            # Solaris 8/9
+        # Solaris 8/9
 
-            ngx_lib_inc="#include <sys/types.h>
+        ngx_lib_inc="#include <sys/types.h>
 #include <md5.h>"
-            ngx_lib="rsaref md5 library"
-            ngx_lib_test="MD5_CTX md5; MD5Init(&md5)"
-            ngx_libs=-lmd5
-            . auto/lib/test
+        ngx_lib="rsaref md5 library"
+        ngx_lib_test="MD5_CTX md5; MD5Init(&md5)"
+        ngx_libs=-lmd5
+        . auto/lib/test
 
 
         if [ $ngx_found = yes ]; then
@@ -64,7 +65,7 @@
 
             ngx_lib="rsaref md library"
             ngx_lib_test="MD5_CTX md5; MD5Init(&md5)"
-            ngx_libs=-lmd
+            #ngx_libs=-lmd
             . auto/lib/test
         fi
 
@@ -76,13 +77,16 @@
             ngx_found=no
 
         else
-            # OpenSSL crypto library
+            if [ $MD5 = NO ]; then
 
-            ngx_inc="#include <openssl/md5.h>"
-            ngx_lib="OpenSSL md5 crypto library"
-            ngx_lib_test="MD5_CTX md5; MD5_Init(&md5)"
-            ngx_libs=-lcrypto
-            . auto/lib/test
+               # OpenSSL crypto library
+
+               ngx_lib_inc="#include <openssl/md5.h>"
+               ngx_lib="OpenSSL md5 crypto library"
+               ngx_lib_test="MD5_CTX md5; MD5_Init(&md5)"
+               ngx_libs=-lcrypto
+               . auto/lib/test
+            fi
         fi
 
 
diff --git a/auto/lib/pcre/conf b/auto/lib/pcre/conf
index a2ab1c6..29c561b 100644
--- a/auto/lib/pcre/conf
+++ b/auto/lib/pcre/conf
@@ -41,6 +41,9 @@
 
     if [ $PLATFORM != win32 ]; then
             PCRE=NO
+            ngx_lib_cflags=
+
+            # Linux
 
             ngx_lib_inc="#include <pcre.h>"
             ngx_lib="PCRE library"
@@ -55,6 +58,7 @@
             CORE_SRCS="$CORE_SRCS $REGEX_SRCS"
             CORE_LIBS="$CORE_LIBS $ngx_libs"
             PCRE=YES
+            ngx_found=no
 
         else
             # FreeBSD PCRE port.
diff --git a/auto/lib/zlib/conf b/auto/lib/zlib/conf
index 9c2178f..37c1fa7 100644
--- a/auto/lib/zlib/conf
+++ b/auto/lib/zlib/conf
@@ -35,8 +35,11 @@
 else
 
     if [ $PLATFORM != win32 ]; then
-        ngx_lib_inc="#include <zlib.h>"
 
+        # FreeBSD, Solaris, Linux
+
+        ngx_lib_cflags=
+        ngx_lib_inc="#include <zlib.h>"
         ngx_lib="zlib library"
         ngx_lib_test="z_stream z; deflate(&z, Z_NO_FLUSH)"
         ngx_libs=-lz
diff --git a/auto/lib/zlib/make b/auto/lib/zlib/make
index 240b647..d256425 100644
--- a/auto/lib/zlib/make
+++ b/auto/lib/zlib/make
@@ -77,8 +77,11 @@
                 done=YES
             ;;
 
+            NO)
+            ;;
+
             *)
-                echo "$0: error: invalid --with-zlib=asm=$ZLIB_ASM option."
+                echo "$0: error: invalid --with-zlib-asm=$ZLIB_ASM option."
                 echo "The valid values are \"pentium\" and \"pentiumpro\" only".
                 echo