diff --git a/.travis.yml b/.travis.yml
index 8dbc64e..176659a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,5 +28,5 @@ after_failure:
 after_script:
   - cat test_gcc_2.txt
 notifications:
-  irc: "chat.freenode.net#libtom"
+  irc: "chat.freenode.net#libtom-notifications"
 
diff --git a/README.md b/README.md
index f1f9171..14e316f 100644
--- a/README.md
+++ b/README.md
@@ -9,3 +9,4 @@ Project Status
 
 master: [![Build Status](https://travis-ci.org/libtom/tomsfastmath.svg?branch=master)](https://travis-ci.org/libtom/tomsfastmath)
 
+develop: [![Build Status](https://travis-ci.org/libtom/tomsfastmath.svg?branch=develop)](https://travis-ci.org/libtom/tomsfastmath)
diff --git a/changes.txt b/changes.txt
index 5b26160..4f86bb9 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,3 +1,9 @@
+April 4th, 2017
+v0.13.1
+     -- Fix missing fp_rand symbol in shared library
+     -- Fix some parameters in API signatures that should've been const
+     -- Bugfixes and improvements contributed by Sebastian Siewior, Reiner Herrmann and Mathias Tausig
+
 October 24th, 2015
 v0.13.0
      -- Add fp_rand()
diff --git a/doc/tfm.pdf b/doc/tfm.pdf
index ef23968..5b560b1 100644
Binary files a/doc/tfm.pdf and b/doc/tfm.pdf differ
diff --git a/libtfm.symbols b/libtfm.symbols
index 01e984b..4147c5d 100644
--- a/libtfm.symbols
+++ b/libtfm.symbols
@@ -31,6 +31,7 @@ fp_mul_d
 fp_mulmod
 fp_prime_random_ex
 fp_radix_size
+fp_rand
 fp_read_radix
 fp_read_signed_bin
 fp_read_unsigned_bin
diff --git a/makefile b/makefile
index 0585eab..b9b3df6 100644
--- a/makefile
+++ b/makefile
@@ -1,7 +1,7 @@
 #makefile for TomsFastMath
 #
 #
-VERSION=0.13
+VERSION=0.13.1
 
 CFLAGS += -Wall -W -Wshadow -Isrc/headers
 
@@ -21,6 +21,22 @@ ifndef MAKE
    MAKE=make
 endif
 
+ifeq ($V,1)
+silent=
+else
+silent=@
+endif
+
+%.o: %.c
+ifneq ($V,1)
+	@echo "   * ${CC} $@"
+endif
+	${silent} ${CC} ${CFLAGS} -c $< -o $@
+
+ifdef COMPILE_DEBUG
+#debug
+CFLAGS += -g3
+else
 ifndef IGNORE_SPEED
 
 CFLAGS += -O3 -funroll-loops
@@ -32,6 +48,7 @@ CFLAGS += -O3 -funroll-loops
 #speed
 CFLAGS += -fomit-frame-pointer
 
+endif
 endif
 
 #START_INS
@@ -103,6 +120,11 @@ install: $(LIBNAME)
 	install -g $(GROUP) -o $(USER) $(LIBNAME) $(DESTDIR)$(LIBPATH)
 	install -g $(GROUP) -o $(USER) $(HEADERS_PUB) $(DESTDIR)$(INCPATH)
 
+HEADER_FILES=$(notdir $(HEADERS_PUB))
+uninstall:
+	rm $(DESTDIR)$(LIBPATH)/$(LIBNAME)
+	rm $(HEADER_FILES:%=$(DESTDIR)$(INCPATH)/%)
+
 .PHONY: mtest
 mtest: $(LIBNAME)
 	cd mtest; CC="$(CC)" CFLAGS="$(CFLAGS) -I../" MAKE=${MAKE} ${MAKE} mtest
@@ -189,9 +211,10 @@ zipup:
 	rm -rf ../tomsfastmath-$(VERSION) && rm -f ../tfm-$(VERSION).zip ../tfm-$(VERSION).tar.bz2 && \
 	expsrc.sh -i . -o ../tomsfastmath-$(VERSION) --svntags --no-fetch -p '*.c' -p '*.h' && \
 	MAKE=${MAKE} ${MAKE} -C ../tomsfastmath-$(VERSION) docs && \
-	tar -c ../tomsfastmath-$(VERSION)/* | bzip2 -9vvc > ../tfm-$(VERSION).tar.bz2 && \
+	tar -c ../tomsfastmath-$(VERSION)/* | xz -cz > ../tfm-$(VERSION).tar.xz && \
+	find ../tomsfastmath-$(VERSION)/ -type f -exec unix2dos -q {} \; && \
 	zip -9 -r ../tfm-$(VERSION).zip ../tomsfastmath-$(VERSION)/* && \
-	gpg -b -a ../tfm-$(VERSION).tar.bz2 && gpg -b -a ../tfm-$(VERSION).zip
+	gpg -b -a ../tfm-$(VERSION).tar.xz && gpg -b -a ../tfm-$(VERSION).zip
 
 new_file:
 	bash updatemakes.sh
diff --git a/makefile.shared b/makefile.shared
index c8dc124..47c35d9 100644
--- a/makefile.shared
+++ b/makefile.shared
@@ -47,7 +47,8 @@ src/sqr/fp_sqr_comba_48.o src/sqr/fp_sqr_comba_4.o src/sqr/fp_sqr_comba_64.o src
 src/sqr/fp_sqr_comba_7.o src/sqr/fp_sqr_comba_8.o src/sqr/fp_sqr_comba_9.o src/sqr/fp_sqr_comba.o \
 src/sqr/fp_sqr_comba_generic.o src/sqr/fp_sqr_comba_small_set.o src/sqr/fp_sqrmod.o
 
-HEADERS=src/headers/tfm.h
+HEADERS_PUB:=src/headers/tfm.h
+HEADERS=src/headers/tfm_private.h $(HEADERS_PUB)
 
 #END_INS
 
@@ -88,13 +89,18 @@ $(OBJECTS): $(HEADERS)
 	$(LTCOMPILE) $(CFLAGS) $(LDFLAGS) -o $@ -c $<
 
 $(LIBNAME): $(OBJECTS)
-	libtool --silent --mode=link --tag=CC $(CC) $(CFLAGS) $(LDFLAGS) `find . -type f | grep "[.]lo" | xargs` -o $(LIBNAME) -rpath $(LIBPATH) -version-info $(VERSION) -export-symbols libtfm.symbols
+	libtool --mode=link --tag=CC $(CC) $(CFLAGS) $(LDFLAGS) `find . -type f | LC_ALL=C sort | grep "[.]lo" | xargs` -o $(LIBNAME) -rpath $(LIBPATH) -version-info $(VERSION) -export-symbols libtfm.symbols
 
 install: $(LIBNAME)
 	install -d -g $(GROUP) -o $(USER) $(DESTDIR)$(LIBPATH)
-	libtool --silent --mode=install install -c $(LIBNAME) $(DESTDIR)$(LIBPATH)/$(LIBNAME)
+	libtool --mode=install install -c $(LIBNAME) $(DESTDIR)$(LIBPATH)/$(LIBNAME)
 	install -d -g $(GROUP) -o $(USER) $(DESTDIR)$(INCPATH)
-	install -g $(GROUP) -o $(USER) $(HEADERS) $(DESTDIR)$(INCPATH)
+	install -g $(GROUP) -o $(USER) $(HEADERS_PUB) $(DESTDIR)$(INCPATH)
+
+HEADER_FILES=$(notdir $(HEADERS_PUB))
+uninstall:
+	libtool --mode=uninstall rm $(DESTDIR)$(LIBPATH)/$(LIBNAME)
+	rm $(HEADER_FILES:%=$(DESTDIR)$(INCPATH)/%)
 
 mtest/mtest: mtest/mtest.c
 	cd mtest ; make mtest
diff --git a/src/generators/comba_sqr_gen.c b/src/generators/comba_sqr_gen.c
index ffd1414..8ebe650 100644
--- a/src/generators/comba_sqr_gen.c
+++ b/src/generators/comba_sqr_gen.c
@@ -9,6 +9,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
 int main(int argc, char **argv)
 {
diff --git a/src/headers/tfm.h b/src/headers/tfm.h
index f406388..a1ed374 100644
--- a/src/headers/tfm.h
+++ b/src/headers/tfm.h
@@ -22,8 +22,8 @@
  * Patch
  * XX - undefined
  */
-#define TFM_VERSION     0x000D0000
-#define TFM_VERSION_S   "v0.13.0"
+#define TFM_VERSION     0x000D0100
+#define TFM_VERSION_S   "v0.13.1"
 
 #ifndef MIN
    #define MIN(x,y) ((x)<(y)?(x):(y))
@@ -252,6 +252,17 @@
    #endif
 #endif
 
+/* use arc4random on platforms that support it */
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
+    #define FP_GEN_RANDOM()    arc4random()
+    #define FP_GEN_RANDOM_MAX  0xffffffff
+#endif
+
+/* use rand() as fall-back if there's no better rand function */
+#ifndef FP_GEN_RANDOM
+   #define FP_GEN_RANDOM()    rand()
+   #define FP_GEN_RANDOM_MAX  RAND_MAX
+#endif
 
 /* some default configurations.
  */
diff --git a/src/misc/fp_rand.c b/src/misc/fp_rand.c
index c1dd766..01198c5 100644
--- a/src/misc/fp_rand.c
+++ b/src/misc/fp_rand.c
@@ -9,7 +9,31 @@
  */
 #include <tfm_private.h>
 
+#if FP_GEN_RANDOM_MAX == 0xffffffff
+  #define FP_GEN_RANDOM_SHIFT  32
+#elif FP_GEN_RANDOM_MAX == 32767
+  /* SHRT_MAX */
+  #define FP_GEN_RANDOM_SHIFT  15
+#elif FP_GEN_RANDOM_MAX == 2147483647
+  /* INT_MAX */
+  #define FP_GEN_RANDOM_SHIFT  31
+#elif !defined(FP_GEN_RANDOM_SHIFT)
+#error Thou shalt define their own valid FP_GEN_RANDOM_SHIFT
+#endif
+
 /* makes a pseudo-random int of a given size */
+static fp_digit fp_gen_random(void)
+{
+  fp_digit d = 0, msk = 0;
+  do {
+    d <<= FP_GEN_RANDOM_SHIFT;
+    d |= ((fp_digit) FP_GEN_RANDOM());
+    msk <<= FP_GEN_RANDOM_SHIFT;
+    msk |= FP_GEN_RANDOM_MAX;
+  } while ((FP_MASK & msk) != FP_MASK);
+  d &= FP_MASK;
+  return d;
+}
 
 void fp_rand(fp_int *a, int digits)
 {
@@ -22,14 +46,14 @@ void fp_rand(fp_int *a, int digits)
 
    /* first place a random non-zero digit */
    do {
-     d = ((fp_digit) abs (rand ())) & FP_MASK;
+     d = fp_gen_random();
    } while (d == 0);
 
    fp_add_d (a, d, a);
 
    while (--digits > 0) {
      fp_lshd (a, 1);
-     fp_add_d (a, ((fp_digit) abs (rand ())), a);
+     fp_add_d (a, fp_gen_random(), a);
    }
 
    return;
diff --git a/tfm.tex b/tfm.tex
index 7bd3159..723f55b 100644
--- a/tfm.tex
+++ b/tfm.tex
@@ -49,7 +49,7 @@
 \begin{document}
 \frontmatter
 \pagestyle{empty}
-\title{TomsFastMath User Manual \\ v0.13.0}
+\title{TomsFastMath User Manual \\ v0.13.1}
 \author{Tom St Denis \\ tomstdenis@gmail.com}
 \maketitle
 This text and library are all hereby placed in the public domain.  This book has been formatted for B5 
@@ -279,6 +279,21 @@ void fp_init_copy(fp_int *a, fp_int *b)
 This will initialize $a$ as a copy of $b$.  Note that for compatibility with LibTomMath the function
 fp\_copy() is also provided.
 
+\subsection{Initialization with a random value}
+To initialize an integer with a random value of a specific length use the fp\_rand() function.
+
+\index{fp\_rand}
+\begin{verbatim}
+void fp_rand(fp_int *a, int digits)
+\end{verbatim}
+
+This will initialize $a$ with $digits$ random digits.
+
+\index{FP\_GEN\_RANDOM} \index{FP\_GEN\_RANDOM\_MAX}
+The source of the random data is \textbf{arc4random()} on *BSD systems that provide this function
+and the standard C function \textbf{rand()} on all other systems. It can be configured at compile time
+by pre-defining \textbf{FP\_GEN\_RANDOM} and \textbf{FP\_GEN\_RANDOM\_MAX}.
+
 \chapter{Arithmetic Operations}
 \section{Odds and Evens}
 To quickly and easily tell if an integer is zero, odd or even use the following functions.