diff --git a/source/rock/frontend/drivers/Driver.ooc b/source/rock/frontend/drivers/Driver.ooc
index 502fd923..711e611a 100644
--- a/source/rock/frontend/drivers/Driver.ooc
+++ b/source/rock/frontend/drivers/Driver.ooc
@@ -95,8 +95,7 @@ Driver: abstract class {
 
         flagsDone addAll(useDef getLibs())
 
-        for(pkg in useDef getPkgs()) {
-            info := PkgConfigFrontend getInfo(pkg)
+        applyInfo := func (info: PkgInfo) {
             for(cflag in info cflags) {
                 if(!flagsDone contains?(cflag)) {
                     flagsDone add(cflag)
@@ -119,6 +118,19 @@ Driver: abstract class {
             }
         }
 
+        for(pkg in useDef getPkgs()) {
+            info := PkgConfigFrontend getInfo(pkg)
+            applyInfo(info)
+        }
+
+        for(pkg in useDef getCustomPkgs()) {
+            info := PkgConfigFrontend getCustomInfo(
+                pkg utilName, pkg names,
+                pkg cflagArgs, pkg libsArgs
+            )
+            applyInfo(info)
+        }
+
         for(includePath in useDef getIncludePaths()) {
             ipath := "-I" + includePath
             if(!flagsDone contains?(ipath)) {
diff --git a/source/rock/frontend/pkgconfig/PkgConfigFrontend.ooc b/source/rock/frontend/pkgconfig/PkgConfigFrontend.ooc
index e5d8593b..3fb1b4c4 100644
--- a/source/rock/frontend/pkgconfig/PkgConfigFrontend.ooc
+++ b/source/rock/frontend/pkgconfig/PkgConfigFrontend.ooc
@@ -34,22 +34,33 @@ PkgConfigFrontend: class {
         cflagArgs: ArrayList<String>, libsArgs: ArrayList<String>) -> PkgInfo {
         utilPath := ShellUtils findExecutable(utilName, true) getPath()
 
-        cflagslist := [utilPath] as ArrayList<String>
-        cflagslist addAll(pkgs)
-        cflagslist addAll(cflagArgs)
-        cflags := _shell(cflagslist)
+        cflags := ""
+        
+        for (cflagArg in cflagArgs) {
+            cflagslist := [utilPath] as ArrayList<String>
+            cflagslist addAll(pkgs)
+            cflagslist add(cflagArg)
+            result := _shell(cflagslist)
+            if(!cflags) {
+                Exception new("Error while running `%s`" format(cflagslist join(" "))) throw()
+            }
 
-        if(cflags == null) {
-            Exception new("Error while running `%s`" format(cflagslist join(" "))) throw()
+            cflags += result
+            cflags += " "
         }
 
-        libslist := [utilPath] as ArrayList<String>
-        libslist addAll(pkgs)
-        libslist addAll(libsArgs)
-        libs := _shell(libslist)
-
-        if(libs == null) {
-            Exception new("Error while running `%s`" format(libslist join(" "))) throw()
+        libs := ""
+        
+        for (libsArg in libsArgs) {
+            libslist := [utilPath] as ArrayList<String>
+            libslist addAll(pkgs)
+            libslist add(libsArg)
+            result := _shell(libslist)
+            if(result == null) {
+                Exception new("Error while running `%s`" format(libslist join(" "))) throw()
+            }
+            libs += result
+            libs += " "
         }
 
         PkgInfo new(pkgs join(" "), libs, cflags)
diff --git a/source/rock/frontend/pkgconfig/PkgInfo.ooc b/source/rock/frontend/pkgconfig/PkgInfo.ooc
index 3ff63294..28e58bb7 100644
--- a/source/rock/frontend/pkgconfig/PkgInfo.ooc
+++ b/source/rock/frontend/pkgconfig/PkgInfo.ooc
@@ -34,6 +34,7 @@ PkgInfo: class {
     init: func (=name, =libsString, =cflagsString) {
         extractTokens("-L", libsString, libPaths)
         extractTokens("-l", libsString, libraries)
+        "For %s, collected libraries: %s" printfln(name, libraries join(", "))
         extractTokens("-I", cflagsString, includePaths)
         extractTokens("", cflagsString, cflags)
     }
diff --git a/source/rock/middle/UseDef.ooc b/source/rock/middle/UseDef.ooc
index 3a7d11b8..633a330f 100644
--- a/source/rock/middle/UseDef.ooc
+++ b/source/rock/middle/UseDef.ooc
@@ -124,15 +124,16 @@ UseDef: class {
     parseCustomPkg: func (value: String) -> CustomPkg {
         vals := value split(',')
         pkg := CustomPkg new(vals[0])
-        pkg names addAll(vals[1] split(' '))
+        pkg names addAll(vals[1] trim() split(' '))
         if (vals size >= 4) {
-            pkg cflagArgs addAll(vals[2] split(' '))
-            pkg libsArgs addAll(vals[3] split(' '))
+            pkg cflagArgs addAll(vals[2] trim() split(' '))
+            pkg libsArgs addAll(vals[3] trim() split(' '))
         } else {
             // If 3rd and 4th argument aren't present, assume pkgconfig-like behavior
             pkg cflagArgs add("--cflags")
             pkg libsArgs add("--libs")
         }
+        pkg
     }
 
     read: func (=file, params: BuildParams) {