diff --git a/Makefile.am b/Makefile.am
index 2123ea3..05ad93a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -13,7 +13,6 @@ lib_LIBRARIES = libkernaux.a
 TESTS = \
 	examples/printf \
 	examples/printf_va \
-	tests/test_elf \
 	tests/test_printf \
 	tests/test_stdlib
 
@@ -42,6 +41,11 @@ if ENABLE_CONSOLE
 libkernaux_a_SOURCES += src/console.c
 endif
 
+if ENABLE_ELF
+libkernaux_a_SOURCES += src/elf.c
+TESTS += tests/test_elf
+endif
+
 if ENABLE_MULTIBOOT2
 libkernaux_a_SOURCES += \
 	src/multiboot2/helpers.c \
diff --git a/configure.ac b/configure.ac
index 8e21252..7bb59b0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,6 +12,7 @@ AC_CANONICAL_HOST
 
 AC_ARG_ENABLE([cmdline],    AS_HELP_STRING([--disable-cmdline],    [disable command line parser]))
 AC_ARG_ENABLE([console],    AS_HELP_STRING([--disable-console],    [disable serial console]))
+AC_ARG_ENABLE([elf],        AS_HELP_STRING([--disable-elf],        [disable ELF utils]))
 AC_ARG_ENABLE([multiboot2], AS_HELP_STRING([--disable-multiboot2], [disable Multiboot 2 information parser]))
 AC_ARG_ENABLE([pfa],        AS_HELP_STRING([--disable-pfa],        [disable Page Frame Allocator]))
 AC_ARG_ENABLE([units],      AS_HELP_STRING([--disable-units],      [disable measurement units utils]))
@@ -20,6 +21,7 @@ AM_CONDITIONAL([ARCH_I386],         [test "$host_cpu" = i386])
 AM_CONDITIONAL([ARCH_X86_64],       [test "$host_cpu" = x86_64])
 AM_CONDITIONAL([ENABLE_CMDLINE],    [test "$enable_cmdline"    != no])
 AM_CONDITIONAL([ENABLE_CONSOLE],    [test "$enable_console"    != no])
+AM_CONDITIONAL([ENABLE_ELF],        [test "$enable_elf"        != no])
 AM_CONDITIONAL([ENABLE_MULTIBOOT2], [test "$enable_multiboot2" != no])
 AM_CONDITIONAL([ENABLE_PFA],        [test "$enable_pfa"        != no])
 AM_CONDITIONAL([ENABLE_UNITS],      [test "$enable_units"      != no])
@@ -28,9 +30,10 @@ AS_IF([test "$host_cpu" = i386],         [AC_DEFINE([ARCH_I386],         [1], [a
 AS_IF([test "$host_cpu" = x86_64],       [AC_DEFINE([ARCH_X86_64],       [1], [architecture is x86_64])])
 AS_IF([test "$enable_cmdline"    != no], [AC_DEFINE([ENABLE_CMDLINE],    [1], [enabled command line parser])])
 AS_IF([test "$enable_console"    != no], [AC_DEFINE([ENABLE_CONSOLE],    [1], [enabled serial console])])
+AS_IF([test "$enable_elf"        != no], [AC_DEFINE([ENABLE_ELF],        [1], [enabled ELF utils])])
 AS_IF([test "$enable_multiboot2" != no], [AC_DEFINE([ENABLE_MULTIBOOT2], [1], [enabled Multiboot 2 information parser])])
 AS_IF([test "$enable_pfa"        != no], [AC_DEFINE([ENABLE_PFA],        [1], [enabled Page Frame Allocator])])
-AS_IF([test "$enable_units",     != no], [AC_DEFINE([ENABLE_UNITS],      [1], [enable measurement units utils])])
+AS_IF([test "$enable_units",     != no], [AC_DEFINE([ENABLE_UNITS],      [1], [enabled measurement units utils])])
 
 AM_INIT_AUTOMAKE([1.9 subdir-objects -Wall -Werror])
 
diff --git a/include/kernaux/elf.h b/include/kernaux/elf.h
index 6a5ee08..0306e57 100644
--- a/include/kernaux/elf.h
+++ b/include/kernaux/elf.h
@@ -72,62 +72,7 @@ typedef struct KernAux_ELF_SectionEntry KernAux_ELF_SectionTable[];
 
 typedef struct KernAux_ELF_RelocationEntry KernAux_ELF_RelocationTable[];
 
-inline static bool KernAux_ELF_Header_is_valid(
-    const struct KernAux_ELF_Header *header
-);
-
-bool KernAux_ELF_Header_is_valid(
-    const struct KernAux_ELF_Header *const header
-) {
-    if (!(
-        header->magic_0x7F     == 0x7F &&
-        header->magic_E        == 'E'  &&
-        header->magic_L        == 'L'  &&
-        header->magic_F        == 'F'  &&
-        header->header_version == 1    &&
-        header->elf_version    == 1
-    )) {
-        return false;
-    }
-
-    if (!(
-        header->bitness == 1 || // 32 bit
-        header->bitness == 2    // 64 bit
-    )) {
-        return false;
-    }
-
-    if (!(
-        header->endianness == 1 || // Little endian
-        header->endianness == 2    // Big endian
-    )) {
-        return false;
-    }
-
-    if (!(
-        header->os_abi >= 0    &&
-        header->os_abi <= 0x12 &&
-        header->os_abi != 0x05
-    )) {
-        return false;
-    }
-
-    if (!(
-        header->obj_type == 0x00   || // NONE
-        header->obj_type == 0x01   || // REL
-        header->obj_type == 0x02   || // EXEC
-        header->obj_type == 0x03   || // DYN
-        header->obj_type == 0x04   || // CORE
-        header->obj_type == 0xFE00 || // LOOS
-        header->obj_type == 0xFEFF || // HIOS
-        header->obj_type == 0xFF00 || // LOPROC
-        header->obj_type == 0xFFFF    // HIPROC
-    )) {
-        return false;
-    }
-
-    return true;
-}
+bool KernAux_ELF_Header_is_valid(const struct KernAux_ELF_Header *header);
 
 #ifdef __cplusplus
 }
diff --git a/src/elf.c b/src/elf.c
new file mode 100644
index 0000000..2d54cc7
--- /dev/null
+++ b/src/elf.c
@@ -0,0 +1,58 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <kernaux/elf.h>
+
+bool KernAux_ELF_Header_is_valid(
+    const struct KernAux_ELF_Header *const header
+) {
+    if (!(
+        header->magic_0x7F     == 0x7F &&
+        header->magic_E        == 'E'  &&
+        header->magic_L        == 'L'  &&
+        header->magic_F        == 'F'  &&
+        header->header_version == 1    &&
+        header->elf_version    == 1
+    )) {
+        return false;
+    }
+
+    if (!(
+        header->bitness == 1 || // 32 bit
+        header->bitness == 2    // 64 bit
+    )) {
+        return false;
+    }
+
+    if (!(
+        header->endianness == 1 || // Little endian
+        header->endianness == 2    // Big endian
+    )) {
+        return false;
+    }
+
+    if (!(
+        header->os_abi >= 0    &&
+        header->os_abi <= 0x12 &&
+        header->os_abi != 0x05
+    )) {
+        return false;
+    }
+
+    if (!(
+        header->obj_type == 0x00   || // NONE
+        header->obj_type == 0x01   || // REL
+        header->obj_type == 0x02   || // EXEC
+        header->obj_type == 0x03   || // DYN
+        header->obj_type == 0x04   || // CORE
+        header->obj_type == 0xFE00 || // LOOS
+        header->obj_type == 0xFEFF || // HIOS
+        header->obj_type == 0xFF00 || // LOPROC
+        header->obj_type == 0xFFFF    // HIPROC
+    )) {
+        return false;
+    }
+
+    return true;
+}