diff --git a/Makefile.am b/Makefile.am
index 1ad3f70..a4e47f3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,13 +25,18 @@ libkernaux_a_SOURCES = \
 	src/libc.c \
 	src/printf.c
 
+if WITH_ARCH_I386
 if ARCH_I386
 libkernaux_a_SOURCES += src/arch/i386/asm.S
 endif
+libkernaux_a_SOURCES += src/arch/i386/paging.c
+endif
 
+if WITH_ARCH_X86_64
 if ARCH_X86_64
 libkernaux_a_SOURCES += src/arch/x86_64/asm.S
 endif
+endif
 
 if WITH_CMDLINE
 libkernaux_a_SOURCES += src/cmdline.c
diff --git a/src/arch/i386/paging.c b/src/arch/i386/paging.c
new file mode 100644
index 0000000..d367e79
--- /dev/null
+++ b/src/arch/i386/paging.c
@@ -0,0 +1,23 @@
+#include <kernaux/arch/i386.h>
+
+// TODO: There are some static asserts just for example.
+
+__attribute__((unused))
+static const int assert0[
+    sizeof(struct KernAux_Arch_I386_PDE) == sizeof(uint32_t) ? 1 : -1
+];
+
+__attribute__((unused))
+static const int assert1[
+    sizeof(struct KernAux_Arch_I386_PTE) == sizeof(uint32_t) ? 1 : -1
+];
+
+__attribute__((unused))
+static const int assert1[
+    sizeof(struct KernAux_Arch_I386_PageDir) == 1024 * sizeof(uint32_t) ? 1 : -1
+];
+
+__attribute__((unused))
+static const int assert1[
+    sizeof(struct KernAux_Arch_I386_PageTable) == 1024 * sizeof(uint32_t) ? 1 : -1
+];