diff --git a/Changelog.md b/Changelog.md
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,9 @@
+### 1.3.0.1
+
+- Fix `pkgconfig-depends` decleration for @use-system-library@
+  configuration; also add new `pkg-config` flag for falling back
+  to non-`pkg-config`-based FFI library linkage.
+
 # 1.3.0.0
 
 - This represents a major rewrite/refactoring of this package.
diff --git a/argon2.cabal b/argon2.cabal
--- a/argon2.cabal
+++ b/argon2.cabal
@@ -1,6 +1,6 @@
 cabal-version:       1.22
 name:                argon2
-version:             1.3.0.0
+version:             1.3.0.1
 
 synopsis:            Memory-hard password hash and proof-of-work function
 description:
@@ -45,10 +45,17 @@
   location: https://github.com/hvr/argon2.git
 
 flag use-system-library
-  description: Link against system @libargon2@ library (discovery via @pkg-config(1)@) rather than using embedded copy of @libargon2@
+  description: Link against system @libargon2@ library rather than using embedded copy of @libargon2@. See also @pkg-config@ flag.
   default: False
   manual: True
 
+flag pkg-config
+  description: Use @pkg-config(1)@ to discover system-library location & flags.
+               .
+               __NOTE__: This has an effect only when the @use-system-library@ flag is also enabled.
+  default: True
+  manual: True
+
 flag non-optimised-c
   description: Force use of non-optimised C routines on @x86_64@. Ineffective when @use-system-library@ flag is active.
   default: False
@@ -72,7 +79,10 @@
 
   if flag(use-system-library)
     cpp-options: -DUSE_SYSTEM_ARGON2=1
-    pkgconfig-depends: argon2
+    if flag(pkg-config)
+      pkgconfig-depends: libargon2 >= 20161029
+    else
+      extra-libraries: argon2
   else
     cpp-options: -DUSE_SYSTEM_ARGON2=0
     c-sources: phc-winner-argon2/src/argon2.c