diff --git a/iguana/exchanges/CMakeLists.txt b/iguana/exchanges/CMakeLists.txt
index 3621418b7..dd97fb81a 100644
--- a/iguana/exchanges/CMakeLists.txt
+++ b/iguana/exchanges/CMakeLists.txt
@@ -1,11 +1,9 @@
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 set(MM_SOURCES mm.c ../mini-gmp.c ../groestl.c ../segwit_addr.c ../keccak.c)
-if (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+    set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1)
+else()
     set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1)
-elseif (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
-    set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1 "-Wl,--allow-multiple-definition")
-elseif (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-    set(MM_LIBS ${NANOMSG_LIBRARY} curl pthread libcrypto777 libjpeg libsecp256k1 "-m")
 endif()
 add_executable(marketmaker-testnet ${MM_SOURCES})
 add_executable(marketmaker-mainnet ${MM_SOURCES})
diff --git a/iguana/secp256k1/CMakeLists.txt b/iguana/secp256k1/CMakeLists.txt
index ae62f1f16..d0e88a3bb 100644
--- a/iguana/secp256k1/CMakeLists.txt
+++ b/iguana/secp256k1/CMakeLists.txt
@@ -1,5 +1,5 @@
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 file(GLOB sources "src/secp256k1.c")
 file(GLOB headers "src/*.h")
-add_definitions(-DHAVE_CONFIG_H)
+add_definitions(-DHAVE_CONFIG_H -DEXTERNAL_SECP256)
 add_library(libsecp256k1 ${sources} ${headers})
\ No newline at end of file
diff --git a/iguana/secp256k1/src/secp256k1.c b/iguana/secp256k1/src/secp256k1.c
index 922caf6cb..4407c6ed8 100644
--- a/iguana/secp256k1/src/secp256k1.c
+++ b/iguana/secp256k1/src/secp256k1.c
@@ -66,6 +66,8 @@ struct secp256k1_context_struct {
     secp256k1_callback error_callback;
 };
 
+#ifndef EXTERNAL_SECP256
+
 secp256k1_context* secp256k1_context_create(unsigned int flags) {
     secp256k1_context* ret = (secp256k1_context*)checked_malloc(&default_error_callback, sizeof(secp256k1_context));
     ret->illegal_callback = default_illegal_callback;
@@ -137,39 +139,6 @@ void secp256k1_context_set_error_callback(secp256k1_context* ctx, void (*fun)(co
     ctx->error_callback.data = data;
 }
 
-static int secp256k1_pubkey_load(const secp256k1_context* ctx, secp256k1_ge* ge, const secp256k1_pubkey* pubkey) {
-    if (sizeof(secp256k1_ge_storage) == 64) {
-        /* When the secp256k1_ge_storage type is exactly 64 byte, use its
-         * representation inside secp256k1_pubkey, as conversion is very fast.
-         * Note that secp256k1_pubkey_save must use the same representation. */
-        secp256k1_ge_storage s;
-        memcpy(&s, &pubkey->data[0], 64);
-        secp256k1_ge_from_storage(ge, &s);
-    } else {
-        /* Otherwise, fall back to 32-byte big endian for X and Y. */
-        secp256k1_fe x, y;
-        secp256k1_fe_set_b32(&x, pubkey->data);
-        secp256k1_fe_set_b32(&y, pubkey->data + 32);
-        secp256k1_ge_set_xy(ge, &x, &y);
-    }
-    ARG_CHECK(!secp256k1_fe_is_zero(&ge->x));
-    return 1;
-}
-
-static void secp256k1_pubkey_save(secp256k1_pubkey* pubkey, secp256k1_ge* ge) {
-    if (sizeof(secp256k1_ge_storage) == 64) {
-        secp256k1_ge_storage s;
-        secp256k1_ge_to_storage(&s, ge);
-        memcpy(&pubkey->data[0], &s, 64);
-    } else {
-        VERIFY_CHECK(!secp256k1_ge_is_infinity(ge));
-        secp256k1_fe_normalize_var(&ge->x);
-        secp256k1_fe_normalize_var(&ge->y);
-        secp256k1_fe_get_b32(pubkey->data, &ge->x);
-        secp256k1_fe_get_b32(pubkey->data + 32, &ge->y);
-    }
-}
-
 int secp256k1_ec_pubkey_parse(const secp256k1_context* ctx, secp256k1_pubkey* pubkey, const unsigned char *input, size_t inputlen) {
     secp256k1_ge Q;
 
@@ -577,14 +546,49 @@ int secp256k1_ec_pubkey_combine(const secp256k1_context* ctx, secp256k1_pubkey *
 # include "modules/ecdh/main_impl.h"
 #endif
 
-#ifdef ENABLE_MODULE_SCHNORR
-# include "modules/schnorr/main_impl.h"
-#endif
-
 #ifdef ENABLE_MODULE_RECOVERY
 # include "modules/recovery/main_impl.h"
 #endif
 
+#endif
+
+static int secp256k1_pubkey_load(const secp256k1_context* ctx, secp256k1_ge* ge, const secp256k1_pubkey* pubkey) {
+    if (sizeof(secp256k1_ge_storage) == 64) {
+        /* When the secp256k1_ge_storage type is exactly 64 byte, use its
+         * representation inside secp256k1_pubkey, as conversion is very fast.
+         * Note that secp256k1_pubkey_save must use the same representation. */
+        secp256k1_ge_storage s;
+        memcpy(&s, &pubkey->data[0], 64);
+        secp256k1_ge_from_storage(ge, &s);
+    } else {
+        /* Otherwise, fall back to 32-byte big endian for X and Y. */
+        secp256k1_fe x, y;
+        secp256k1_fe_set_b32(&x, pubkey->data);
+        secp256k1_fe_set_b32(&y, pubkey->data + 32);
+        secp256k1_ge_set_xy(ge, &x, &y);
+    }
+    ARG_CHECK(!secp256k1_fe_is_zero(&ge->x));
+    return 1;
+}
+
+static void secp256k1_pubkey_save(secp256k1_pubkey* pubkey, secp256k1_ge* ge) {
+    if (sizeof(secp256k1_ge_storage) == 64) {
+        secp256k1_ge_storage s;
+        secp256k1_ge_to_storage(&s, ge);
+        memcpy(&pubkey->data[0], &s, 64);
+    } else {
+        VERIFY_CHECK(!secp256k1_ge_is_infinity(ge));
+        secp256k1_fe_normalize_var(&ge->x);
+        secp256k1_fe_normalize_var(&ge->y);
+        secp256k1_fe_get_b32(pubkey->data, &ge->x);
+        secp256k1_fe_get_b32(pubkey->data + 32, &ge->y);
+    }
+}
+
+#ifdef ENABLE_MODULE_SCHNORR
+# include "modules/schnorr/main_impl.h"
+#endif
+
 #ifdef ENABLE_MODULE_RANGEPROOF
 # include "modules/rangeproof/main_impl.h"
 #endif