diff --git a/install-cmake.sh b/install-cmake.sh
index cb9bde26..7019b268 100755
--- a/install-cmake.sh
+++ b/install-cmake.sh
@@ -38,6 +38,14 @@
 
 # Define constants.
 #==============================================================================
+# Branches for github dependencies.
+#------------------------------------------------------------------------------
+SECP256K1_BRANCH="v0.5.1"
+BITCOIN_SYSTEM_BRANCH="master"
+BITCOIN_NETWORK_BRANCH="master"
+BITCOIN_DATABASE_BRANCH="master"
+BITCOIN_NODE_BRANCH="master"
+
 # Sentinel for comparison of sequential build.
 #------------------------------------------------------------------------------
 SEQUENTIAL=1
@@ -919,22 +927,22 @@ build_all()
     export CPPFLAGS="$CPPFLAGS ${BOOST_FLAGS[@]}"
     build_from_tarball_boost "$BOOST_ARCHIVE" "$PARALLEL" "$BUILD_BOOST" "${BOOST_OPTIONS[@]}"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github bitcoin-core secp256k1 v0.5.1 "$BUILD_SECP256K1"
+    create_from_github bitcoin-core secp256k1 ${SECP256K1_BRANCH} "$BUILD_SECP256K1"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${SECP256K1_FLAGS[@]}"
     build_from_github secp256k1 "$PARALLEL" false "$BUILD_SECP256K1" "${SECP256K1_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-system master "yes"
+    create_from_github libbitcoin libbitcoin-system ${BITCOIN_SYSTEM_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_SYSTEM_FLAGS[@]}"
     build_from_github_cmake libbitcoin-system "$PARALLEL" false "yes" "${BITCOIN_SYSTEM_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-network master "yes"
+    create_from_github libbitcoin libbitcoin-network ${BITCOIN_NETWORK_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NETWORK_FLAGS[@]}"
     build_from_github_cmake libbitcoin-network "$PARALLEL" false "yes" "${BITCOIN_NETWORK_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-database master "yes"
+    create_from_github libbitcoin libbitcoin-database ${BITCOIN_DATABASE_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_DATABASE_FLAGS[@]}"
     build_from_github_cmake libbitcoin-database "$PARALLEL" false "yes" "${BITCOIN_DATABASE_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
@@ -942,7 +950,7 @@ build_all()
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NODE_FLAGS[@]}"
     if [[ ! ($CI == true) ]]; then
-        create_from_github libbitcoin libbitcoin-node master "yes"
+        create_from_github libbitcoin libbitcoin-node ${BITCOIN_NODE_BRANCH} "yes"
         build_from_github_cmake libbitcoin-node "$PARALLEL" true "yes" "${BITCOIN_NODE_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     else
         push_directory "$PRESUMED_CI_PROJECT_PATH"
diff --git a/install-cmakepresets.sh b/install-cmakepresets.sh
index e695eff3..3aee9647 100755
--- a/install-cmakepresets.sh
+++ b/install-cmakepresets.sh
@@ -39,6 +39,14 @@
 
 # Define constants.
 #==============================================================================
+# Branches for github dependencies.
+#------------------------------------------------------------------------------
+SECP256K1_BRANCH="v0.5.1"
+BITCOIN_SYSTEM_BRANCH="master"
+BITCOIN_NETWORK_BRANCH="master"
+BITCOIN_DATABASE_BRANCH="master"
+BITCOIN_NODE_BRANCH="master"
+
 
 # Declare associative array for computed presets.
 #------------------------------------------------------------------------------
@@ -962,24 +970,24 @@ build_all()
     export CPPFLAGS="$CPPFLAGS ${BOOST_FLAGS[@]}"
     build_from_tarball_boost "$BOOST_ARCHIVE" "$PARALLEL" "$BUILD_BOOST" "${BOOST_OPTIONS[@]}"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github bitcoin-core secp256k1 v0.5.1 "$BUILD_SECP256K1"
+    create_from_github bitcoin-core secp256k1 ${SECP256K1_BRANCH} "$BUILD_SECP256K1"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${SECP256K1_FLAGS[@]}"
     build_from_github secp256k1 "$PARALLEL" false "$BUILD_SECP256K1" "${SECP256K1_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-system master "yes"
+    create_from_github libbitcoin libbitcoin-system ${BITCOIN_SYSTEM_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_SYSTEM_FLAGS[@]}"
     display_message "libbitcoin-system PRESET ${REPO_PRESET[libbitcoin-system]}"
     build_from_github_cmake libbitcoin-system ${REPO_PRESET[libbitcoin-system]} "$PARALLEL" false "yes" "${BITCOIN_SYSTEM_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-network master "yes"
+    create_from_github libbitcoin libbitcoin-network ${BITCOIN_NETWORK_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NETWORK_FLAGS[@]}"
     display_message "libbitcoin-network PRESET ${REPO_PRESET[libbitcoin-network]}"
     build_from_github_cmake libbitcoin-network ${REPO_PRESET[libbitcoin-network]} "$PARALLEL" false "yes" "${BITCOIN_NETWORK_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-database master "yes"
+    create_from_github libbitcoin libbitcoin-database ${BITCOIN_DATABASE_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_DATABASE_FLAGS[@]}"
     display_message "libbitcoin-database PRESET ${REPO_PRESET[libbitcoin-database]}"
@@ -988,7 +996,7 @@ build_all()
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NODE_FLAGS[@]}"
     if [[ ! ($CI == true) ]]; then
-        create_from_github libbitcoin libbitcoin-node master "yes"
+        create_from_github libbitcoin libbitcoin-node ${BITCOIN_NODE_BRANCH} "yes"
         display_message "libbitcoin-node PRESET ${REPO_PRESET[libbitcoin-node]}"
         build_from_github_cmake libbitcoin-node ${REPO_PRESET[libbitcoin-node]} "$PARALLEL" true                     "yes" "${BITCOIN_NODE_OPTIONS[@]}" $CUMULATIVE_FILTERED_ARGS_CMAKE "$@"
     else
diff --git a/install.sh b/install.sh
index b2d37b3d..158ab5d1 100755
--- a/install.sh
+++ b/install.sh
@@ -38,6 +38,14 @@
 
 # Define constants.
 #==============================================================================
+# Branches for github dependencies.
+#------------------------------------------------------------------------------
+SECP256K1_BRANCH="v0.5.1"
+BITCOIN_SYSTEM_BRANCH="master"
+BITCOIN_NETWORK_BRANCH="master"
+BITCOIN_DATABASE_BRANCH="master"
+BITCOIN_NODE_BRANCH="master"
+
 # Sentinel for comparison of sequential build.
 #------------------------------------------------------------------------------
 SEQUENTIAL=1
@@ -794,22 +802,22 @@ build_all()
     export CPPFLAGS="$CPPFLAGS ${BOOST_FLAGS[@]}"
     build_from_tarball_boost "$BOOST_ARCHIVE" "$PARALLEL" "$BUILD_BOOST" "${BOOST_OPTIONS[@]}"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github bitcoin-core secp256k1 v0.5.1 "$BUILD_SECP256K1"
+    create_from_github bitcoin-core secp256k1 ${SECP256K1_BRANCH} "$BUILD_SECP256K1"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${SECP256K1_FLAGS[@]}"
     build_from_github secp256k1 "$PARALLEL" false "$BUILD_SECP256K1" "${SECP256K1_OPTIONS[@]}" "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-system master "yes"
+    create_from_github libbitcoin libbitcoin-system ${BITCOIN_SYSTEM_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_SYSTEM_FLAGS[@]}"
     build_from_github libbitcoin-system "$PARALLEL" false "yes" "${BITCOIN_SYSTEM_OPTIONS[@]}" "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-network master "yes"
+    create_from_github libbitcoin libbitcoin-network ${BITCOIN_NETWORK_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NETWORK_FLAGS[@]}"
     build_from_github libbitcoin-network "$PARALLEL" false "yes" "${BITCOIN_NETWORK_OPTIONS[@]}" "$@"
     export CPPFLAGS=$SAVE_CPPFLAGS
-    create_from_github libbitcoin libbitcoin-database master "yes"
+    create_from_github libbitcoin libbitcoin-database ${BITCOIN_DATABASE_BRANCH} "yes"
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_DATABASE_FLAGS[@]}"
     build_from_github libbitcoin-database "$PARALLEL" false "yes" "${BITCOIN_DATABASE_OPTIONS[@]}" "$@"
@@ -817,7 +825,7 @@ build_all()
     local SAVE_CPPFLAGS="$CPPFLAGS"
     export CPPFLAGS="$CPPFLAGS ${BITCOIN_NODE_FLAGS[@]}"
     if [[ ! ($CI == true) ]]; then
-        create_from_github libbitcoin libbitcoin-node master "yes"
+        create_from_github libbitcoin libbitcoin-node ${BITCOIN_NODE_BRANCH} "yes"
         build_from_github libbitcoin-node "$PARALLEL" true "yes" "${BITCOIN_NODE_OPTIONS[@]}" "$@"
     else
         push_directory "$PRESUMED_CI_PROJECT_PATH"