diff --git a/CMakeLists.txt b/CMakeLists.txt
index b859bc43..2944510f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -211,16 +211,28 @@ if(NOT MSVC)
     find_package(PkgConfig)
 endif()
 
-file(READ "include/xlsxwriter.h" ver)
+# Set some variables for the xlsxwriter.pc file and the .so version.
+# ------------------------------------------------------------------
+set(PREFIX ${CMAKE_INSTALL_PREFIX})
 
+file(READ "include/xlsxwriter.h" ver)
 string(REGEX MATCH "LXW_VERSION \"([^\"]+)\"" _ ${ver})
 set(VERSION ${CMAKE_MATCH_1})
 string(REGEX MATCH "LXW_SOVERSION \"([^\"]+)\"" _ ${ver})
 set(SOVERSION ${CMAKE_MATCH_1})
-set(PREFIX ${CMAKE_INSTALL_PREFIX})
 
+set(ENABLED_OPTIONS "zlib")
+if(USE_SYSTEM_MINIZIP)
+    string(APPEND ENABLED_OPTIONS " minizip")
+endif()
+if(USE_OPENSSL_MD5)
+    string(APPEND ENABLED_OPTIONS " libcrypto")
+endif()
+
+# Expand out the xlsxwriter.pc file.
 configure_file(dev/release/pkg-config.txt xlsxwriter.pc @ONLY)
 
+
 # INCLUDES
 # --------
 enable_language(CXX)
diff --git a/Makefile b/Makefile
index d90b0d2c..4bbaa4ca 100644
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,14 @@ PYTESTFILES ?= test
 VERSION   = $(shell sed -n -e 's/.*LXW_VERSION \"\(.*\)\"/\1/p'   include/xlsxwriter.h)
 SOVERSION = $(shell sed -n -e 's/.*LXW_SOVERSION \"\(.*\)\"/\1/p' include/xlsxwriter.h)
 
+ENABLED_OPTIONS = zlib
+ifdef USE_SYSTEM_MINIZIP
+    ENABLED_OPTIONS += minizip
+endif
+ifdef USE_OPENSSL_MD5
+	ENABLED_OPTIONS += libcrypto
+endif
+
 .PHONY: docs tags examples third_party
 
 # Build libxlsxwriter.
@@ -164,7 +172,11 @@ install: all
 	$(Q)mkdir -p        $(DESTDIR)$(PREFIX)/lib
 	$(Q)cp -R lib/*     $(DESTDIR)$(PREFIX)/lib
 	$(Q)mkdir -p        $(DESTDIR)$(PREFIX)/lib/pkgconfig
-	$(Q)sed -e          's|@PREFIX@|$(PREFIX)|g'  -e 's|@VERSION@|$(VERSION)|g' dev/release/pkg-config.txt > $(DESTDIR)$(PREFIX)/lib/pkgconfig/xlsxwriter.pc
+	$(Q)sed             -e 's|@PREFIX@|$(PREFIX)|g'                   \
+	                    -e 's|@VERSION@|$(VERSION)|g'                 \
+	                    -e 's|@ENABLED_OPTIONS@|$(ENABLED_OPTIONS)|g' \
+	                        dev/release/pkg-config.txt                \
+	                        > $(DESTDIR)$(PREFIX)/lib/pkgconfig/xlsxwriter.pc
 
 # Simpler uninstall.
 uninstall:
diff --git a/dev/release/pkg-config.txt b/dev/release/pkg-config.txt
index a87d080c..8aff13eb 100644
--- a/dev/release/pkg-config.txt
+++ b/dev/release/pkg-config.txt
@@ -7,4 +7,5 @@ Name: libxlsxwriter
 Description: A C library for creating Excel XLSX files
 Version: @VERSION@
 Cflags: -I${includedir}
-Libs: -L${libdir} -lxlsxwriter -lz
+Libs: -L${libdir} -lxlsxwriter
+Requires.private: @ENABLED_OPTIONS@