diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -228,6 +228,7 @@
 	-Wredundant-decls
 	-Wunreachable-code-loop-increment
 	-Wsign-compare
+	-Wconditional-uninitialized
 )
 add_compiler_flag_group(-Wformat -Wformat-security)
 add_cxx_compiler_flags(
diff --git a/src/leveldb/CMakeLists.txt b/src/leveldb/CMakeLists.txt
--- a/src/leveldb/CMakeLists.txt
+++ b/src/leveldb/CMakeLists.txt
@@ -16,6 +16,7 @@
 	-Wno-shadow
 	-Wno-sign-compare
 	-Wno-unused-const-variable
+	-Wno-conditional-uninitialized
 )
 add_c_compiler_flags(-Wno-strict-prototypes)
 
diff --git a/src/random.cpp b/src/random.cpp
--- a/src/random.cpp
+++ b/src/random.cpp
@@ -119,7 +119,10 @@
     // this risk.
 #ifdef __i386__
     uint8_t ok;
-    uint32_t r1, r2;
+    // Initialize to 0 to silence a compiler warning that r1 or r2 may be used
+    // uninitialized. Even if rdrand fails (!ok) it will set the output to 0,
+    // but there is no way that the compiler could know that.
+    uint32_t r1 = 0, r2 = 0;
     for (int i = 0; i < 10; ++i) {
         // rdrand %eax
         __asm__ volatile(".byte 0x0f, 0xc7, 0xf0; setc %1"
@@ -139,7 +142,7 @@
     return (uint64_t(r2) << 32) | r1;
 #elif defined(__x86_64__) || defined(__amd64__)
     uint8_t ok;
-    uint64_t r1;
+    uint64_t r1 = 0; // See above why we initialize to 0.
     for (int i = 0; i < 10; ++i) {
         // rdrand %rax
         __asm__ volatile(".byte 0x48, 0x0f, 0xc7, 0xf0; setc %1"