diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7d5defe8..5f73d505 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -111,6 +111,7 @@ if(AARE_FETCH_MINUIT2)
     Minuit2
     GIT_REPOSITORY https://github.com/GooFit/Minuit2.git
     GIT_TAG v6-40-02
+    GIT_SHALLOW TRUE
     UPDATE_DISCONNECTED 1)
   # Disable Minuit2 extras we don't need
   set(minuit2_mpi
@@ -128,6 +129,10 @@ if(AARE_FETCH_MINUIT2)
   FetchContent_MakeAvailable(Minuit2)
 
   set_property(TARGET Minuit2Math PROPERTY POSITION_INDEPENDENT_CODE ON)
+  # Minuit2 is ~60 small files; compiling them in batches is several times
+  # faster
+  set_target_properties(Minuit2 Minuit2Math
+                        PROPERTIES UNITY_BUILD ON UNITY_BUILD_BATCH_SIZE 16)
   set_property(TARGET Minuit2 PROPERTY POSITION_INDEPENDENT_CODE ON)
 
   add_library(aare::Minuit2 ALIAS Minuit2)
@@ -165,6 +170,7 @@ if(AARE_ZMQ)
       libzmq
       GIT_REPOSITORY https://github.com/zeromq/libzmq.git
       GIT_TAG v4.3.5
+      GIT_SHALLOW TRUE
       PATCH_COMMAND ${ZMQ_PATCH_COMMAND}
       UPDATE_DISCONNECTED 1)
     # Disable unwanted options from libzmq
@@ -198,6 +204,14 @@ if(AARE_ZMQ)
       FetchContent_Populate(libzmq)
       add_subdirectory(${libzmq_SOURCE_DIR} ${libzmq_BINARY_DIR}
                        EXCLUDE_FROM_ALL)
+      # libzmq compiles its sources into the OBJECT library "objects" (on
+      # Windows directly into libzmq-static); batch them like Minuit2
+      foreach(_zmq_target objects libzmq-static)
+        if(TARGET ${_zmq_target})
+          set_target_properties(
+            ${_zmq_target} PROPERTIES UNITY_BUILD ON UNITY_BUILD_BATCH_SIZE 16)
+        endif()
+      endforeach()
     endif()
   else()
     find_package(ZeroMQ 4 REQUIRED)
@@ -218,6 +232,7 @@ if(AARE_FETCH_FMT)
     fmt
     GIT_REPOSITORY https://github.com/fmtlib/fmt.git
     GIT_TAG 12.1.0
+    GIT_SHALLOW TRUE
     GIT_PROGRESS TRUE
     USES_TERMINAL_DOWNLOAD TRUE)
   set(FMT_INSTALL
diff --git a/RELEASE.md b/RELEASE.md
index 71778f51..1a6df702 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -16,6 +16,9 @@
 - libzmq is only fetched or searched for with ``-DAARE_ZMQ=ON`` (default
   OFF) and is then available as ``aare::zmq``. Nothing in aare links it yet,
   and skipping it removes about 8 s from every CMake configure.
+- Minuit2, and libzmq when enabled, are compiled as unity builds (about 5x
+  less compile time), and the fetched dependencies are shallow clones, which
+  makes a first configure faster and the build directory smaller.
 
 ## 2026.9.30
 
diff --git a/benchmarks/CMakeLists.txt b/benchmarks/CMakeLists.txt
index e874a003..fab3fa19 100644
--- a/benchmarks/CMakeLists.txt
+++ b/benchmarks/CMakeLists.txt
@@ -6,7 +6,7 @@ FetchContent_Declare(
   benchmark
   GIT_REPOSITORY https://github.com/google/benchmark.git
   GIT_TAG v1.8.3 # Change to the latest version if needed
-)
+  GIT_SHALLOW TRUE)
 
 # Ensure Google Benchmark is built correctly
 set(BENCHMARK_ENABLE_TESTING
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 7f4db4c0..db7974f3 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -11,7 +11,8 @@ if(AARE_FETCH_PYBIND11)
   FetchContent_Declare(
     pybind11
     GIT_REPOSITORY https://github.com/pybind/pybind11
-    GIT_TAG v3.0.3)
+    GIT_TAG v3.0.3
+    GIT_SHALLOW TRUE)
   FetchContent_MakeAvailable(pybind11)
 else()
   find_package(pybind11 3.0.3 REQUIRED)