diff --git a/pkgs/development/libraries/openssl/1.0.1-cygwin64.patch b/pkgs/development/libraries/openssl/1.0.1-cygwin64.patch
deleted file mode 100644
index 63112abf3a39..000000000000
--- a/pkgs/development/libraries/openssl/1.0.1-cygwin64.patch
+++ /dev/null
@@ -1,136 +0,0 @@
---- openssl-1.0.1e/config      2014-10-23 15:53:23.436600000 +0200
-+++ openssl-1.0.1e/config      2014-10-23 15:55:33.837000000 +0200
-@@ -832,6 +832,7 @@
-   # these are all covered by the catchall below
-   # *-dgux) OUT="dgux" ;;
-   mips-sony-newsos4) OUT="newsos4-gcc" ;;
-+  x86_64-*-cygwin) OUT="Cygwin-x86_64" ;;
-   *-*-cygwin_pre1.3) OUT="Cygwin-pre1.3" ;;
-   *-*-cygwin) OUT="Cygwin" ;;
-   t3e-cray-unicosmk) OUT="cray-t3e" ;;
---- openssl-1.0.1e/Configure	2013-02-17 17:06:18.682058900 -0600
-+++ openssl-1.0.1e/Configure	2013-02-17 16:38:08.000000000 -0600
-@@ -550,6 +550,7 @@ my %table=(
- "Cygwin-pre1.3", "gcc:-DTERMIOS -DL_ENDIAN -fomit-frame-pointer -O3 -m486 -Wall::(unknown):CYGWIN32::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${no_asm}:win32",
- "Cygwin", "gcc:-DTERMIOS -DL_ENDIAN -fomit-frame-pointer -O3 -march=i486 -Wall:::CYGWIN32::BN_LLONG ${x86_gcc_des} ${x86_gcc_opts}:${x86_asm}:coff:dlfcn:cygwin-shared:-D_WINDLL:-shared:.dll.a",
- "debug-Cygwin", "gcc:-DTERMIOS -DL_ENDIAN -march=i486 -Wall -DBN_DEBUG -DREF_CHECK -DCONF_DEBUG -DBN_CTX_DEBUG -DCRYPTO_MDEBUG -DOPENSSL_NO_ASM -g -Wformat -Wshadow -Wmissing-prototypes -Wmissing-declarations -Werror:::CYGWIN32:::${no_asm}:dlfcn:cygwin-shared:-D_WINDLL:-shared:.dll.a",
-+"Cygwin-x86_64", "gcc:-DTERMIOS -DL_ENDIAN -O3 -Wall:::CYGWIN32::SIXTY_FOUR_BIT_LONG RC4_CHUNK DES_INT DES_UNROLL:${x86_64_asm}:mingw64:dlfcn:cygwin-shared:-D_WINDLL:-shared:.dll.a",
- 
- # NetWare from David Ward (dsward@novell.com)
- # requires either MetroWerks NLM development tools, or gcc / nlmconv
-@@ -1128,7 +1129,7 @@ foreach (sort @experimental)
- 
- my $IsMK1MF=scalar grep /^$target$/,@MK1MF_Builds;
- 
--$exe_ext=".exe" if ($target eq "Cygwin" || $target eq "DJGPP" || $target =~ /^mingw/);
-+$exe_ext=".exe" if ($target =~ /^Cygwin/ || $target eq "DJGPP" || $target =~ /^mingw/);
- $exe_ext=".nlm" if ($target =~ /netware/);
- $exe_ext=".pm"  if ($target =~ /vos/);
- $openssldir="/usr/local/ssl" if ($openssldir eq "" and $prefix eq "");
---- openssl-1.0.1e/Makefile.org	2013-02-11 09:26:04.000000000 -0600
-+++ openssl-1.0.1e/Makefile.org	2013-02-17 16:38:08.000000000 -0600
-@@ -326,9 +326,9 @@ clean-shared:
- 			done; \
- 		fi; \
- 		( set -x; rm -f lib$$i$(SHLIB_EXT) ); \
--		if [ "$(PLATFORM)" = "Cygwin" ]; then \
-+		case "$(PLATFORM)" in Cygwin*)  \
- 			( set -x; rm -f cyg$$i$(SHLIB_EXT) lib$$i$(SHLIB_EXT).a ); \
--		fi; \
-+		esac; \
- 	done
- 
- link-shared:
-@@ -571,11 +571,7 @@ install_sw:
- 		do \
- 			if [ -f "$$i" -o -f "$$i.a" ]; then \
- 			(       echo installing $$i; \
--				if [ "$(PLATFORM)" != "Cygwin" ]; then \
--					cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
--					chmod 555 $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
--					mv -f $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i; \
--				else \
-+				case "$(PLATFORM)" in Cygwin*) \
- 					c=`echo $$i | sed 's/^lib\(.*\)\.dll\.a/cyg\1-$(SHLIB_VERSION_NUMBER).dll/'`; \
- 					cp $$c $(INSTALL_PREFIX)$(INSTALLTOP)/bin/$$c.new; \
- 					chmod 755 $(INSTALL_PREFIX)$(INSTALLTOP)/bin/$$c.new; \
-@@ -583,7 +579,12 @@ install_sw:
- 					cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
- 					chmod 644 $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
- 					mv -f $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i; \
--				fi ); \
-+					;; \
-+				*) \
-+					cp $$i $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
-+					chmod 555 $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new; \
-+					mv -f $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i.new $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/$$i; \
-+				esac ); \
- 				if expr $(PLATFORM) : 'mingw' > /dev/null; then \
- 				(	case $$i in \
- 						*crypto*) i=libeay32.dll;; \
-@@ -643,9 +644,9 @@ install_docs:
- 	@pod2man="`cd ./util; ./pod2mantest $(PERL)`"; \
- 	here="`pwd`"; \
- 	filecase=; \
--	if [ "$(PLATFORM)" = "DJGPP" -o "$(PLATFORM)" = "Cygwin" -o "$(PLATFORM)" = "mingw" ]; then \
-+	case "$(PLATFORM)" in DJGPP|Cygwin*|mingw*) \
- 		filecase=-i; \
--	fi; \
-+	esac; \
- 	set -e; for i in doc/apps/*.pod; do \
- 		fn=`basename $$i .pod`; \
- 		sec=`$(PERL) util/extract-section.pl 1 < $$i`; \
---- openssl-1.0.1e/engines/ccgost/Makefile	2013-02-11 09:26:04.000000000 -0600
-+++ openssl-1.0.1e/engines/ccgost/Makefile	2013-02-17 17:05:47.759290200 -0600
-@@ -45,7 +45,11 @@ install:
- 		set -e; \
- 		echo installing $(LIBNAME); \
- 		pfx=lib; \
--		if [ "$(PLATFORM)" != "Cygwin" ]; then \
-+		case "$(PLATFORM)" in Cygwin*) \
-+			sfx=".so"; \
-+			cp cyg$(LIBNAME).dll $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx.new; \
-+			;; \
-+		*) \
- 			case "$(CFLAGS)" in \
- 			*DSO_BEOS*) sfx=".so";; \
- 			*DSO_DLFCN*) sfx=`expr "$(SHLIB_EXT)" : '.*\(\.[a-z][a-z]*\)' \| ".so"`;; \
-@@ -54,10 +58,7 @@ install:
- 			*) sfx=".bad";; \
- 			esac; \
- 			cp $${pfx}$(LIBNAME)$$sfx $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx.new; \
--		else \
--			sfx=".so"; \
--			cp cyg$(LIBNAME).dll $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx.new; \
--		fi; \
-+		esac; \
- 		chmod 555 $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx.new; \
- 		mv -f $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx.new $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$${pfx}$(LIBNAME)$$sfx; \
- 	fi
---- openssl-1.0.1i/engines/Makefile	2014-10-23 16:08:19.360200000 +0200
-+++ openssl-1.0.1i/engines/Makefile	2014-10-23 16:10:54.205800000 +0200
-@@ -111,7 +111,11 @@
- 		for l in $(LIBNAMES); do \
- 			( echo installing $$l; \
- 			  pfx=lib; \
--			  if [ "$(PLATFORM)" != "Cygwin" ]; then \
-+			  case "$(PLATFORM)" in Cygwin*) \
-+				sfx=".so"; \
-+				cp cyg$$l.dll $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx.new; \
-+				;; \
-+			  *) \
- 				case "$(CFLAGS)" in \
- 				*DSO_BEOS*)	sfx=".so";;	\
- 				*DSO_DLFCN*)	sfx=`expr "$(SHLIB_EXT)" : '.*\(\.[a-z][a-z]*\)' \| ".so"`;;	\
-@@ -120,10 +124,7 @@
- 				*)		sfx=".bad";;	\
- 				esac; \
- 				cp $$pfx$$l$$sfx $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx.new; \
--			  else \
--				sfx=".so"; \
--				cp cyg$$l.dll $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx.new; \
--			  fi; \
-+			  esac; \
- 			  chmod 555 $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx.new; \
- 			  mv -f $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx.new $(INSTALL_PREFIX)$(INSTALLTOP)/$(LIBDIR)/engines/$$pfx$$l$$sfx ); \
- 		done; \
diff --git a/pkgs/development/libraries/openssl/default.nix b/pkgs/development/libraries/openssl/default.nix
index 8582c0a1833e..0d07513634fb 100644
--- a/pkgs/development/libraries/openssl/default.nix
+++ b/pkgs/development/libraries/openssl/default.nix
@@ -22,7 +22,6 @@ let
       ++ [ ./nix-ssl-cert-file.patch ]
       ++ optional (versionOlder version "1.1.0")
           (if stdenv.isDarwin then ./use-etc-ssl-certs-darwin.patch else ./use-etc-ssl-certs.patch)
-      ++ optional stdenv.isCygwin ./1.0.1-cygwin64.patch
       ++ optional
            (versionOlder version "1.0.2" && (stdenv.isDarwin || (stdenv ? cross && stdenv.cross.libc == "libSystem")))
            ./darwin-arch.patch;